Direct Observation of Oil Consumption Mechanisms In a
Production Spark Ignition Engine
Using Fluorenscence Techniques
by
Roderick M. Lusted
B. A., Chemistry; Saint Olaf College, 1977
Submitted to the Departments of
Ocean Engineering and Mechanical Engineering
in Partial Fulfillment of the Requirements for the Degrees of
NAVAL ENGINEER
and
MASTER OF SCIENCE IN MECHANICAL ENGINEERING
at the
Massachusetts Institute of Technology
May 1994
© 1994 Roderick M. Lusted.
All rights reserved.
The author hereby grants to MIT permission to reproduce and
to distribute publicly paper and electronic copies of this
document in whole or in part.
Signature of Author
Department gOcean Engineering
May 1990
S•-Th /
Certified by
Professor,
Dr. Alan J. Brown
epartment of Ocean Engineering
Thesis Reader
Certified by
Dr. Victor W. Wong
Lecturer, Department of Mechanical Engineering
Thesis Advisor
Accepted by
-A. DouglasCICYatchael, Chairman
Departmental Committee on Graduate Studies
D~"egtment of Ocean Engineering
Acepted by
A. A. Sonin, Chairman
Departmental Committee on Graduate Studies
Department of Mechanical Engineering
," SIV I
''
-A
i
This Page Intentionally Blank
Direct Observation of Oil Consumption Mechanisms In a
Production Spark Ignition Engine
Using Fluorescence Techniques
by
Roderick M. Lusted
Submitted to the Departments of
Ocean Engineering and Mechanical Engineering
in Partial Fulfillment of the Requirements for the Degrees of
NAVAL ENGINEER
and
MASTER OF SCIENCE IN MECHANICAL ENGINEERING
ABSTRACT
The oil consumption characteristics of a four cylinder,
normally aspirated spark-ignition engine were investigated for
different piston ring end-gap configurations. A radiotracer
was used to perform direct measurement of the oil consumption
while Laser-induced Fluorescence (LIF) was used to perform the
oil film thickness measurements for consumption predictions
using the "Puddle Theory of Oil Consumption," which relates
oil consumption to second land film thickness and reverse flow
through top ring gap. The consumption data was evaluated to
determine the impact of top ring end-gap azimuthal location on
oil consumption. The film thickness data was used to evaluate
the extent to which the Oil Puddle Theory predicts variations
seen in the actual oil consumption.
A tritium radiotracer oil consumption measurement system
with an accuracy of 94.6% was designed and constructed. This
was used to perform direct measurements of the test engine oil
consumption in two different test matrices. The first
evaluated a piston ring configuration with the rings free to
rotate. The second evaluated configurations with the top ring
and second piston rings pinned to fix the azimuthal location
of the end-gap; the azimuth of the top ring was varied. In
the second test matrix, the oil film thickness on the piston's
second land was measured, and predictions were made on the
basis of that measurement.
The first test matrix results indicated only a weak speed
dependence and a large amount of variability in the oil
consumption measurements.
The second test matrix results showed an oil consumption
speed dependence that was a function of top gap azimuth.
Speed normalized results showed that the oil consumption was
larger when the end-gap was on the thrust side of the test
engine than when on the anti-thrust side.
Measured oil consumpti6n differed substantially from that
in
This was found to be due to difficulties
predicted.
determining effective ring gap flow areas and due to a
previously un-documented azimuthal variation in second land
However, analysis of the results also
oil film thickness.
indicates that the Puddle Theory is still a plausible oil
consumption mechanism.
Thesis Supervisor:
Title:
Dr. Victor W. Wong
Lecturer,
Department
Engineering
of
Mechanical
Dedication
This thesis is dedicated to the three people who have
paid the highest price for its successful completion: my wife,
Patricia, and my two sons, Ethan and Kevin.
To the three of you, thank you for your unwavering love
and support.
This Page Intentionally Blank
Acknowledgements
Dr. Victor Wong, my thesis advisor, has provided a
special kind of freedom and support in this project. He has
accommodated the idiosyncracies of my Navy schedule with
understanding and flexibility.
CAPT Alan Brown provided the initial inspiration to begin
the project.
the' Dana Corporation, provided
Fiedler, of
Dave
inspiration throughout the project with his keen interest and
practical advice.
Dr. David Hoult provided shrewd experimental insight at
several critical junctures in the project.
Don Fitzgerald and Brian Corkum each provided practical
insight and guidance to overcome many of the technical
hurdles. Very few projects would ever "get off the ground" in
the Sloan Automotive Engine Laboratory without them. If I had
spent more time actively seeking their advise, I would have
wasted a lot less time.
LCDR Greg Thomas whose personal sacrifice of family time
as the Submarine Design Project leader allowed me the
flexibility to complete this project.
F. D. Tamai and Tian Tian gave selflessly of their time
whenever I need their help; you both proved to be "shipmates"
in the finest sense of the word! A special thanks to Tian for
patching me up when I did foolish things to myself.
LT R. B. Lawrence, Janice Dearlove, Mike Norris each
provided friendship and encouragement in just the right
measure to make the lab a fun and exciting place to work.
The U. S. Navy allowed me the "time-off from work" to
complete this thesis and the course work that formed the basis
for it.
To all of you my most sincere gratitude. I wish you all
"fair winds and following seas" in what ever endeavors you put
your hands and minds to in the future.
R. Mark Lusted
CDR,
USN
6 May 1994
7
This Page Intentionally Blank
Table of Contents
ABSTRACT
Dedication
. . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .. . . ...
Acknowledgements
. ................
Table of Contents . .....
.
. . . .
5
. .
7
.
9
............
. . .
3
. .
.
11
Chapter 1: Introduction and Background . .......
1.1 Motivation . . . . . . . . . . .. . . . . . .
..........
.
1.2 Mechanisms .....
..
.
1.3 Previous Work . . . . . . . . . . . . .
.........
1.4 Objectives . ........
15
15
18
20
22
.
.
.
23
23
23
26
32
35
List of Abbreviations . . . . . . . . ...
.......
... . .
Chapter 2: Theory . . . . .
. . . . . . . . . . . . . . . . .
2.1 General
2.2 Piston Ring End-gap Gas Flow . . . . . . .
2.3 The Puddle Theory of Oil Consumption . . .
2.4 Radiotracer Oil Consumption Measurement . .
2.5 Fluorescence Measurements . . . . . . . . .
Chapter 3: Equipment Setup and Instrumentation . .
3.1 General . . . . . . . . . . . . . . . . .
3.2 Engine Description . . . . . . . . . . .
3.3 Laser Induced Fluorescence System (LIF) .
3.4 Radiotracer Oil Consumption System (ROCS)
3.5 Data Acquisition System . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
43
43
43
45
49
52
Chapter 4: Experimental Procedures . ........
.
4.1 General . . . . . ...
............
.
4.2 Water Collection System Design . ......
4.3 Test Matrices . . . . . . . . . . . . . . . .
4.4 Engine/Dynamometer Operating Procedures . . .
4.5 Radiotracer Method Validation Procedures
.
4.6 LIF/Data Collection System . . . . . . . . .
4.7 Piston Replacement Procedures.
. . . . . . .
4.8
Radiotracer Oil Consumption Measurement
Procedures . . .
...
.
. ........
4.9 Radiological Safety . ............
53
53
53
58
66
66
67
67
Chapter 5: Results and Discussion of Results . . . . .
5.1 General . . . . ......... .........
.
5.2
Radiotracer
Oil
Consumption
System
Evaluation . . . . . . . . . . . . . . . . .
5.3 Data Reduction . . . . . . . . . . . . . . .
70
70
67
68
70
71
77
5.4 Test Matrix C (Unpinned Rings) Results . . .
Test Matrix AZ (Azimuthally Pinned Rings)
5.5
Results . . . . . . . .
5.6 Application of the Shaw
. . . . .
Consumption
.
Results
5.7 Discussion of
Continuing Investigations . . . .
. . .
. .
.. . . . .
...
. . . . . . . .
Calculations
Appendix B:
Equipment
Appendix C:
Operating Procedures and Logs
. . . .
. . .
.
.
.
.
. . .
.
. . .
Appendix A:
89
94
. . 104
. . 104
. . 104
. . 106
for
. . . . . . 107
Conclusions and Recommendations . . .
Chapter 6
6.1 General . . . . . . . . . . . . . . . .
.......
..
6.2 Conclusions . ....
. . . . .
Analysis.
6.3 Further Study and
Observations
and
Recommendations
6.4
References
78
. . . . . . . . . . .
Puddle Theory of Oil
. . . .
. . . . . . . .
....
114
. . . . 116
S..
138
. . . . . .
147
. . . .
. .
ROCS Validation and Evaluation . . . . . . 171
Appendix D:
D.1 General . . . . . . . . . . . . . . . . . . . 171
171
D.2 Error Evaluation . . . . . . . . . . .
173
.
.
.
D.3 Performance Optimization
175
Modifications
D.4 System Summary and Future
S.
Appendix E:
Oil Consumption Spreadsheets . . .
Appendix
Basic Routines . . . .
Appendix G:
Photographs of Piston Deposit Patterr is .
. . . . . . .
.
178
188
195
List of Abbreviations
a
Absorptivity (1/[gm*cm])
A
Area; used to indicate orifice cross-sectional
area in general and the area of the effective
oil puddle under the top ring gap (mm12
AP
Area of the oil puddle (mm)2 .
Aref
Reference area in the Shaw Model (mm12
A*
Non-dimensionalized oil puddle radius.
b
optical sample path length (cm).
bmep
Brake Mean Effective Pressure (kPa).
c
Speed of sound (m/s) or sample concentration
(gm/liter).
Cd
Coefficient of Drag.
D
Piston to cylinder wall clearance (mm).
DAS
Data Acquisition System
d,
Diameter of the second land (cm or m).
f
Coefficient of Friction (N/N).
g
Top piston ring end-gap (mm).
hi
Initial oil film thickness in the oil puddle
(mm).
HC
Total Unburned Hydrocarbons; normally measured
in ppm C,.
HCA
Total Hydrocarbon Analyzer
HDD
Heavy Duty Diesels
hý
Non-dimensionalized Ah.
k
Proportionality constant for surface tension
(N/I [mK] ).
Kpa
kilo-Pascal
LIF
Laser Induced Fluorescence System
12
Length of the second land (mm).
LDV
Light Duty Vehicles
LSC
Liquid Scintillation Counter
m
Walther's
viscosity
correlation
negative
slope.
mV
milli-Volt
N
Walther's viscosity correlation intercept.
OC
Lubricating Oil Consumption rate;
the units
vary through out.
OU
DAS output unit (4.88 mV)
P
Used in Section 2.5 to mean luminous power of
a fluorescence transmitted light; elsewhere,
pressure in kPa.
PMT
Photomultiplier Tube
Po
Luminous power of a light source.
PCV
Positive Crankcase Ventillation
PM
Exhaust Particulate Matter; normally measured
in grams.
Q
Volumetric flow rate of RBB gases through the
top ring gap.
R,r
Oil
puddle
radius:
maximum
and
general
respectively.
RBB
Reverse Blowby:
The gases traveling through
the top ring gap into the crown land region.
RF
Radio Fluorescence.
ROCS
Radiotracer Oil Consumption System
Shaw Model
Shaw Puddle Theory of Oil Consumption
SI
"Spark Ignition" gasoline engine
(as opposed
to a diesel or "compression ignition".)
Ta
"Taylor number" =. (J*U)/a
Ti
Temperature of the second land (oK)
To
Reference temperature for surface tension (oK)
tmx
The time duration between top ring transition
from the bottom to the top of the ring groove
until peak RBB.
U
Average gas velocity over the oil puddle.
v(r)
Gas velocity over the oil puddle.
WCS
Exhaust Water Collection System (a subsystem
of the ROCS)
WOT
Wide Open Throttle
z
Axial piston coordinate measured down from the
crown (mm).
GREEK CHARACTERS
Ah
Change in oil film thickness in the oil puddle
under the top ring gap due to oil removed by
reverse blowby.
factor for gases.
SCompressibility
e
Azimuthal piston coordinate measured form the
13
from of the .,piston (degrees)
SWavelength
(nm).
Low shear dynamic viscosity.
ta
v
Dynamic viscosity of air.
Kinematic
viscosity
(mm2/sec
in
Walther's
equantion; m 2/sec elsewhere).
p
Density
(the specific substance for which it
is. used varies throughout the thesis.
Po
The
density
of
the
lubricating
oil
at
a
reference temperature.
3
Low shear surface tension.
Equivalence ratio ([fuel:air]/[fuel:air]stoich)
14
IntroductiQn and Background
Chapter 1:
1.1 Motivation
Lubricating oil consumption (OC) in internal combustion
engines has historically been of concern from an economic
basis; the oil consumed in an hour of operation has to be
replaced at some cost and with some impact on engine operating
profile.
The magnitude of the problem varies from a spark-
ignition automobile engine consuming approximately four grams
of oil per operating hour (0.43 g/bhp-hr)l
to large marine
diesels consuming approximately three kilograms of oil per
operating hour (0.37 g/bhp-hr)2 .
More recently concern has been raised over the part OC
plays in engine emissions.
Lubricating oil admitted to the
combustion chamber contributes to Total Unburned Hydrocarbons
(HC) and other gases in engine exhaust streams.
In the case
of diesel engines, oil consumption has also been found to
contribute to exhaust particulate matter (PM).
Unburned Hydrocarbons are composed of a variety of polar
and non-polar organic compounds ranging from simple alkanes to
substituted cyclo-alkenes and aliphatic ketones.3
'Experimentally determined data
engine.
2PHONECON
for a Chrysler 2.2
liter
with Hal Furlucci, Caterpiller, Inc. dtd 11 April
1994.
3Reference
Depending
1, pg. 598.
on
their
reactivity,
these, compounds
contribute
to
the
formation of photochemical smog. Analysis of diesel engine PM
indicates
that
compounds.4
the
adsorbed
HC
contain
carcinogenic
Growing public concern over the environment has
given rise to legislation that provides aggressive emissions
standards
for
such
varied: internal
combustion
engine
applications as onroad vehicles (automobiles and trucks) and
large ships (both U. S. Navy and civilian) operating within
waters
Table 1-1 is a
contiguous to the United States.
listing of some of the standards for Light Duty
partial
Vehicles (LDV).
Table 1-1:
Regulatory Standards for HC and PM5
Exhaust
CAA Standard
CAA Standard
Typical
Constituent
1996
2003
Emission for
(Projected)
Light Duty
Vehicle
HC
0.31
grams/mile
0.125
grams/mile
1.36
grams/mile
PM
0.10
grams/mile
0.10
grams/mile
0.3 to 1.07
grams/mile
For both HC and PM, current LDV emissions must be reduced
significantly to meet even 1996 standards.
4Reference
Exhaust catalysis
1, pg. 597.
SSection 202, Federal Clean Air Act (CAA)
6Based
upon Road Load calculated for an SI powered economy car
using Equation 2.18c from Reference 1, exhaust HC concentration of
750 ppm (low end of the expected band) and stoichiometric
operation; 95% catalyst efficiency is assumed.
7Reference
1, pg. 626.
16
provides only a partial sollution to the challenge of meeting
the current and future HC standards.
Typical automotive
catalysts operate at a maximum of 95 percent efficiency for
oxidation of HC.
This indicates that methods must be found to
reduce exhaust port HC levels.
('HDD). standards differ
Heavy-duty diesel
from those
applied to LDV's because they are written on a grams per brake
Table 1-28 shows the PM standards for
horsepower hour basis.
HDD by model year.
Table 1-2:
Regulatory PM Standards for HDD
Model Year
Standard
(g/bhp-hr)
1990
0.60
1991
0.25
1994
0.10
0.05
1996*
New urban buses only
With the current aggressive standards and the potential for
more stringent standards in the future, all potential methods
for reducing emissions have to be examined.
As engine designs are refined to allow for more efficient
fuel combustion, the relative contribution of oil consumption
to
total
hydrocarbon
increasingly important.
and
particulate
emissions
becomes
Tests conducted by Wentworth on a
spark ignition engine in 1982 indicate that approximately 30
percent of total HC concentration in a spark ignition engine
8Reference
2, pg. 1.
Current HDD emissions
exhaust comes from oil consumption.'
reduction schemes require the reduction of the lubricating oil
To the
contribution to exhaust port emissions by 30%.1o
extent that lubricating oil plays a part in emissions, it is
of benefit to understand the OC mechanisms to allow engine and
lubricant designs to include OC in their optimization scheme.
1.2 Mechanisms
Lubricating Oil is consumed by an internal combustion
engine via three basic paths:
a. Valve stem leakage (Overhead),
b.
Positive Crankcase Vacuum (PCV) flow, and
c.
Piston ring leakage.
Table 1-311 shows
the relative contributions of the three
sources; the largest contributor is the latter.
Table 1-3:
Relative Contribution OC Paths
Path
% of Total
(Range Reported)
Piston
Overhead
15.6 to 55.2
PCV
7.3 to 10.1
Piston Ring Leakage
38.7 to 77.1
ring
leakage
can
'Reference 3.
10Reference
2, Figure 2.
1 1Reference
4.
be broken
down
into
two
broad
mechanisms:
a.
Flow past the ring face, and
b.
Flow through the ring gap.
The contribution of the first mechanism is relatively minor;
Wahiduzzaman et al. estimated that evaporative consumption of
oil on the cylinder wall accounted for between two and five
percent
of
total
studies
thickness
oil
consumption'",
shown
have
the
that
oil
film
land
runs
and piston
crown
consistently dry indicating the inertial introduction of oil
The
into the combustion process is negligible.
dominant
mechanism for OC is flow through the compression ring
(top
ring) end-gap.
Shaw advanced the
"Puddle Theory of Oil Consumption"
(Shaw Model) via flow through the end-gap."
The Shaw Model
states that the oil admitted to the combustion chamber through
the
top
ring
end-gap is governed by
the velocity of
the
reverse blow-by (RBB) gases 14 over the "puddle" of oil under
the top ring end-gap (the geometry is shown in Figure 1-1), by
the
depth
of
the puddle
and
by
viscosity of the oil in that puddle.
the
surface
tension and
The peak RBB velocity is
governed by the cylinder pressure profile, the piston geometry
12Reference
5.
3Reference
6.
14Gases flowing from the second land, through the top ring gap
and into the crown land area.
TOP
RING *
TOP RING
PUDDLE
2nd RING
GIAP
LANi~Dj
3rd
LAND
SCALE
Figure 1-1: Geometry of the Oil Puddle Model
and cylinder geometry. 5s
1.3 Previous Work
In 1990 Hartman investigated oil consumption in a single
cylinder Kubota diesel engine with unpinned rings"6 ; he found
considerable variability in the data.
experiments
direct
designed
oil
to validate
consumption
In 1991, Shaw conducted
the
measurements
Puddle
and
Theory
Laser
using
Induced
Fluorescence measurement of oil film thickness on the same
1SReference
7.
1
" Reference
8.
20
single cylinder Kubota engine with pinned rings"7 ; he was
able to achieve a reduced variability in the data and an 84
percent
correlation between experimentally determined and
calculated oil consumption.
Figure 1-218 shows a comparison
between Hartman's results and those of Shaw.
OC:
Unpinned Rings vs.
Pinned Rings
SAE-30
4.9 -
Oa
04
1.3 --
1.2 1.1
131
08-
4.7
0 70a
1-
+
I
I
0 4
0 32
0.1
I
0
1.5
1.7
1.9
2.1
2.3
2.7
2.5
2.9
CThoLamnd)
a
Engn•r
Pfnned CShaw:
5peed CRPJo
+ Unrlnned CHartnmrO
Figure 1-2
Both the Heywood-Namazian model for gas flow and the Shaw
Model
initially
geometry.
17Reference
assume
However,
a
constant
factors
like
end-gap/second
bore
distortion,
9.
18
Transcription of Figure 4-1, Reference 9.
21
land
ring
rotation 19 and piston secondary 20 motion are factors that may
cause that geometry to vary cycle-to-cycle and within a cycle.
1.4 Objectives
The objectives of this research are three fold:
a.
Establish and validate a reliable method of directly
measuring engine oil consumption.
Use the above method to observe the effect of top
b.
ring
gap
azimuth
on
oil
consumption
mechanisms
in
a
production, SI engine.
c.
Combine the results of Objective b with simultaneous
LIF measurements to observe the correlation between Shaw Model
predictions of OC via ring-gap and actual OC for different top
ring gap orientations.
"gReference 10.
2 0Reference
11.
Chapter 2:
2.1
Theory
General
The theory presented in this chapter covers both the
basic mechanisms and measurements involved in this project.
Additional theories and hypotheses used in the analysis of the
experimental results will be presented in Chapter 5.
The piston coordinate system used in this paper is shown
in Figure 2-1.
2.2
Piston Ring End-gap Gas
Flow
To predict an engine's
it
OC,
to
necessary
is
Theta
calculate the gas velocities
in
the piston
ring reaion.
(Front)
Namazian
and
Heywood
model
for
presented
a
flow
the
in
piston
crevice regions21
a
gas
ring
z
that uses
one-dimensional
(z
-I-
dimension)
descriptions
of
the continuity equation for
Figure 2-1:
System
Pisto n Coordinate
each crevice (Figure 2-222 ) and the ring motion.
2 1Reference
7,
2 2Reference
7, Figure 15.
pp 10-13.
a.
Continuity (assuming isothermal conditions):
dP)/p
m( dt
where:
)
.
(2.1)
region index, i = 1 to 5 (See Fig.
2-2),
moi is the initial mass in the ith
region and
Poi is the initial pressure in the
ith region.
Combustion Chamber
Region
Rings
-
-
Figure 2-2:
b.
Plane
.A
P
ng
·
Piston Ring Crevice Regions
1-D equation of motion for the ring:
(2.2)
) =F,+F,+FF,-F,
M (_
where the variables are those shown in Figure 2-3.
Additionally,
flow
between
regions
is
described
as
orficial flow and the mass flow rate is given by:
(2.3)
fh= fCdAp c
where:
fCd = 0.6
A
is the orfice area
p
is the gas density
c
is the speed of sound
T1
is the compressiblity factor of
the gas.
Ff
Fp
Pressure
F1
Friction force
Fi
Inertia force
Fs
Oil resistance force
Oil film
Figure 2-3:
Piston Ring Force Diagram
force
The
program
described
GASFLOW23
above
uses
with
a
the
Namazian-Heywood
cylinder
pressure
model
profile
to
iteratively calculate the gas flow rates and ring positions
for an input engine geometry. The outputs of the program used
to predict OC in this study were the top ring gap volume
flowrate for reverse blowby and the top ring axial position
profile.
2.3
The Puddle Theory of Oil Consumption
Shaw hypothesized that, during engine operation, it is
primarily the lubricating oil which accumulates on the second
land immediately under the top ring gap which contributes to
oil
consumption. 24
observations
This hypothesis
is born
out
in
the
made by Namazian and Heywood in transparent
engine experiments".
These indicate that a portion of the
second land oil film is blown into the crown land region and
the combustion chamber by the reverse blowby (RBB) during a
short burst
or
"jet"
of high velocity flow.
This high
velocity flow coincides with the top ring transition from the
bottom of the ring groove to the top of the ring groove and is
driven by the change in the sign of the pressure differential
between the combustion chamber and the second land during the
expansion stroke.
"Copyright (C) by Hoult and Company, September 1990.
24Reference
9, Chapter 5.
25Reference
7, pg. 11.
26
Geometry
The region of second land oil film effected by the gas
flow can be thought of as a semi-circular puddle.
The Puddle
'2 t
)
Piston Dimensions used in Oil Consumption Model.
Figure 2-4
Theory geometry is
shown in Figure 2-4.26
Where Q is
the
volume flow rate of the RBB gases, g is the top ring gap, d2
is the piston diameter at the second land,
12
the second land and r is the puddle radius.
26Reference
9, 5-1.
is the length of
Figure 2-4 shows
the limiting puddle size which is used as the reference area
The puddle area and reference area are given by
(Aref).
equations 2.4 and 2.5.
= ZZ
2
2
(2.4)
and
Ae x (12)
(2.5)
The oil transfered in this process is given by the equation:
(2.6)
OC pahA,
or
S OC
(2.7)
where p is the oil density at the temperature of the second
land, Ah is the change in the depth of the oil puddle during
the oil transfer and A, is the area of the oil puddle.
Shaw non-dimensionalized the puddle area
(A*) and the
change in puddle depth (h*) as follows27 :
A*e= (2
Aref (U2e) 2
27The
20C
pChl
(2.8)
2
definitions for h* differs between Reference 6 and
Reference 9; the definition shown here is that given in Reference
6.
28
and
h*where:
(2.9)
h i is the second land oil film prior
to top ring transition.
Motive Force
The mass fraction of liquid expelled from a tube with gas
flowing through it was shown by Taylor to be a function of the
viscosity of the liquid, the velocity of the gas and the
surface tension of the liquid2 8 . He formed a non-dimensional
quantity which will be called the Taylor number in this paper.
T. =I(2.10)
Treating the second land geometry like a tube terminating in
the top and second ring gaps, Shaw used the volume flow rate
of the gas through the top ring gap to determine the average
gas velocity over the oil puddle as follows.
The gas velocity
as a function of puddle radius may be expressed:
v(Z)- crD
where:
D
is the
(2.11)
clearance
between
second land and the liner.
The velocity is then radially averaged:
2 8Reference
12, pg. 161.
29
the
R-
1
D) dr
f2(xID
g=
(2.12)
2 g/l2
or
v=
Q
R
xD (R-g/2) In( g/2
(2.13)
R
and
(2.14)
Non-dimensional Parameters
Shaw showed empirically that A* and h* are functions of
the
Taylor
number
according
to
the
shown
relationships
below.29
A*=15.28 (Ta) -2/3
(2.15)
and
i.3 U(t
) Ta4 /(3
412
where:
U
is
(2.16)
+0.61
the
average
gas
flow
velocity over the puddle,
~a
is
the
dynamic
viscosity
of
the
dynamic
viscosity
of
air,
.1
29Reference
pg. 82.
is
oil,
tmax
is the time (in seconds) from
top
until
transition
ring
maximum RBB, and
12
in the length (z dimension) of
the second land.
Fluid Properties
The physical properties of the lubricating oil used were
obtained from the following empirical relationships:
a.
Density (in
kg/m3):
(2.17)
p=Po-O.63 (T1 -T o )
b. Low shear surface tension (a) (in N/m):
a=k(Ti-To) +ao
where:
T,
(2.18)
is the second land temperature
in degrees K
•o
is the surface tension at the
reference temperature To.
k
is
the
surface
proportionality
tension
constant
that
is lubricant specific.
c.
Low shear kinematic viscosity (v)
(in rmm/sec):
logo0 log a0 (v+0. 6) =-mloglo (T2 ) +N
where:
m
and
N
constants
are
(2.19)
empirically
supplied
by
derived
the
manufacturer.
d.
Low shear dynamic viscosity (l):
(2.20)
P=vp
Oil Consumption
Using the above relationships, the oil consumption in
grams per hour can be calculated:
(2.21)
OC= (0.03) RPMphh2*AzA*
hi
where:
and
Aref
are
in
mm
and
mm2
respectively, and
p is in g/ml.
where
initial
film
thickness
and
must
be
input
from
experimentally determined data.
Inspection of the above scheme for determining the OC
reveals that the calculation is not closed-form:
the non-
dimensional
must
parameters
and
the
Taylor
number
be
iteratively calculated to achieve an internally consistent
solution.
In practice, it is beneficial to determine as many
of the physical parameters as possible to limit the degrees of
freedom involved in the solution.
2.4
Radiotracer Oil Consumption Measurement
In this research, measurement of the actual engine oil
consumption is done using a radiotracer technique.
technique,
lubricating oil
is doped
32
through
In this
a catalytic
exchange process where a fraction of the atomic hydrogen in
the lubricant sample is exchanged for tritium which is a low
energy beta emitter. Lubricant involved in a combustion event
in the cylinder is exhausted as water, carbon dioxide, carbon
monoxide, unburned/partially burned hydrocarbons and compounds
of
in various degrees
sulfur
of oxidation.
If
all the
compounds in the exhaust are subsequently completely oxidized
through
catalysis
or
other
means,
all
exhaust
stream
constituents will be converted to oxides; the consequence of
this fully oxidized state is that all the hydrogen and tritium
atoms will be included in the exhaust water.
The specific
activity of the water can be stoichiometricly related by
equation 2.22 to the specific activity of the oil to give the
fraction of all engine water that comes from the oil.
CH,+(
4
) (O2 +3.773N
2+ (
2 )-CO
where:
2
)H20+(
4
)N2
(2.22)
n is the Hydrogen to Carbon ration
for
the
fuel
(typically 1.87
for
gasoline)
The only non-organic source of exhaust water vapor is the
humidity in the air; this can be compensated for by including
the air in the calculation.
If the fuel and air flow rates
and the specific humidity are known, the oil total consumption
rate
can
then
be
calculated
from
the
stoichiometry
of
combustion.
For a spark ignition engine not operating at a wide open
33
(WOT)
throttle
condition,
= 1)
1 may be assumed.
(equivalence ratio,
operation
stoichiometric
This assumption
was made for this study and the air flow was not measured.
If, however, the engine is not operating at a stoichiometric
mixture, the air flow or the equivalence ratio must be known.
The chemical equation then becomes:
CFl_+ -1+ A] (O2+3.773N2)-*co 2+'H
l+3.773(
a-) N2 (2.23)
2
As the equivalence ratio decreases, the specific humidity
increases in relative importance.
calculation
The equations used for OC
are detailed by Warrick
and Dykehouse.30
A
typical radiotracer OC calculation can be found in Appendix A.
As discussed in Chapter One, soot
is a much larger
exhaust constituent for diesel engines than for Spark-ignition
(SI) engines.
Since soot contains a significant fraction of
the HC emitted from a diesel engine, it must be taken into
account when performing OC measurements on diesels.
test
engine for this
study was a SI engine,
Since the
it was not
necessary to consider soot; however, the measurements and
assumptions
necessary
combustion products
3oReference
to
account
adsorbed
14, Appendix A.
on the
for
lubricating
soot particles
oil
were
discussed by Hartman."
2.5
Fluorescence Measurements
Since
this
study
and
(LIF)
Fluorescence
makes
Radio
use
of
both
Fluorescence
Laser
Induced
(RF),
it
is
Some
worthwhile to review the fundamentals of fluorescence.
chemical species absorb excitation energy (light, ionizing
radiation, etc.) and dissipate the absorbed energy by emitting
L
Chemical
sample
sample
P
o
P
o
c
a
/ L-
L
A
.1. 1)iagrani
B
showing isotropic luminescence
produced
by
ablsorptioi of racdiatio ifrom incident beam of power Po. Radiant power (L)
oif IUltIli lcscr"cr is solle friaction of the radiant power absorbed (Po - P).
B, ('hangcs ill cnI,'rgy of a chemical species during absorption (A) and
r'c(lsnalcI(
It''orlllscIli (F). Resonance fluorescence is a special luminescence
1 ""'"
Figure 2-5:
31Reference
Luminescence Process
8, pg. 11.
light.3 2
shows
This property is.'called luminescence.
that while the incident
directional,
Figure 2-5
and transmitted light
are
the emitted light is isotropic; this feature
proves useful in some detector geometries.
The power of the emitted light (L) is given by:
L=k (Po-P)
where:
(2.24)
Po
is the incident light power,
P
is the transmitted light power,
k
is the proportionality constant
related
to
the
quantum
efficiency for luminescence of
the species.
This relationship can be restated substituting the LambertBeer relationship:
(2.25)
L=kP, (1-10 c)
where:
a
is absorptivity (gm-1 cm- 1) ,
b
is sample path length (cm) and
c
is
sample
concentration
(gm/liter).
Using the first term of the Taylor series expansion of an
exponential,' equation 2.25 becomes:
32Reference
15, pg. 606.
36
(2.26)
L=2.3kPeabc=k'Peabc
where:
k'
is a proportionality constant
modified
to
include
the
conversion factor from base 10
to base e.
This provides a linear relationship that can be used over a
limited
range
of
concentration."
The
relationship
is
analytically useful because the emitted light can be measured
using a photomultiplier tube (PMT) which generates a current
proportional to concentration and/or path length.
Luminescence can be broken down into two categories:
fluorescence and phosphorescence.
The different electron
energy state changes involved in luminescence are shown in
Figure 2-6.
On a basic level, the difference between these two is the
relaxation process time constant.
Fluorescent processes have
a time constant between 109 and 106 sec -I while phosphorescent
processes
Because of
have time constants between 106
the
short
time constant,
and 10-' sec-1 .
fluorescence can
be
thought of as "real time" which is an advantage, but also can
present difficulties.
The advantage is that it can be used as
an in-line, point measurement technique since the response
time is
3 "This
short; it
is perfect for real-time data acquisition
demonstrates why fluorimetry must be calibrated close
to the path length and concentration measured.
T2
VR
V0
G
Electronic energy-level diagram for a molecule
wich ground state (G) and excited singict (S) and triplet
(T) states. Radiationless transitions between states are represented by wavy arrows; A is absorption, F is fluorescence,
P is phosphorescence, VR is vibrational relaxation. IX is
intersystem crossing, and IC is internal convcrsion. (See text
for discussion.)
Figure 2-6:
systems.
Electron Transitions for Luminescent Processes
The
difficulties
arise
in
separating
the
simultaneous fluorescent contributions of varing species and
contribution of the incident light to the signal presented to
the
PMT.
An
additional
complication
luminescence is "quenching."
in
both
types
of
Quenching refers to the self
absorption of the luminescent light by the sample itself.
Laser Induced Fluorescence
Laser Induced Fluorescence, as used in this application,
38
nm Filton
Focusing
442
495
442
He Cd Laser
Coupler
mn
PMT
Figure 2-7:
Focusing Assembiy and 495 nm Filters
LIF Schematic
uses visible light (X = 442nm) to stimulate a fluorescent dye
at a constant concentration in the lubricating oil to measure
the "sample path length" and thereby determine the oil film
thickness.
Shaw
instrumentation
gives
involved
a
detailed
in
this
description
technique ",
of
the
and
Lee
provides a detailed description of the specific geometry used
in the test engine'".
Figure 2-736 shows schematically the
34Reference
9, Appendices A and B.
3SReference
16, pp 13-23.
39
LIF sampling geometry.
In practice the incident light and the
fluorescent light travel the same optical path through the
focusing probe; there is a 53nm difference in the wavelength
of the laser and the fluorescent spectral peak of the dye
which allows bandpass filtration to be used to eliminate the
contribution of the incident light.
impact
factors
Other
technique"7 .
Among
these
the
are
of
accuracy
PMT
power
the
LIF
stability,
temperature effects on dye concentration and on quenching, and
precision in focussing probe positioning.
The impact of all
of these factors is that LIF film thickness traces require
calibration.
LIF calibration uses a salient feature of known
measurement on the piston (such as tooling marks or a ring
profile)
that
is
observable
on
the
trace.
A
constant
calibration factor is then applied to the entire trace to
adjust the feature to the correct dimensional measurement.
The calibration features selected for this
study were the
tooling marks on the piston skirt.
Radio Fluorescence
The Radiotracer method for determining oil consumption
relies on the use of radio fluorescence for determining the
concentration of tritium in the oil and water samples.
The
samples are mixed with a solution containing an excess of a
compound that fluoresces when subjected to beta radiation.
36Reference
17, Figure 4.
37Reference
18.
The
individual
fluorescent
events
(scintillations)
are
detected in a Liquid Scintillation Counter which reads out in
Decays
per Minute
(dpm).
The
beta
radiation
flux
(the
equivalent of the P0 or incident power) is determined with the
species concentration and sample path length (discussed above)
held constant.
Po is then used to determine the specific
activity 38 of the tritium which is measured in dpm per gram of
sample.
Correctly determining the amount of quenching is
crucial in liquid scintillation counting and each sample must
be analyzed for absorption at the measured wavelength. Figure
2-8 shows a typical quench curve for tritium analysis.
The
parameter "tSIE" is a measure of the transmittance (P/Po) of
the sample and is dependent on the color and clarity of the
sample.
The
counting
efficiency
is
a
measure
of
the
percentage of actual scintillations detected by the liquid
scintillation counter.
The lower the efficiency the poorer
the statistical sample of scintillations and the greater the
error in sample activity for a given counting time.
the results
achieved from highly quenched samples
improved by extended counting times.
became
samples
a problem in oil
gave
counting
However,
can be
In this study, quenching
samples.
If
undiluted,
efficiencies
of
approximately
the oil
five
percent with the corresponding specific activities varying by
38The
specific activity is a measure of the tritium
concentration; however, it is most convenient to work strictly in
specific activity units (dpm/gram or pCi/gram) as long as only one
radionuclide is involved.
as
much
as
reliability
±100%.
of
OiT
sample
dilution
the results without
improved
extending the counting
times.
Quench Curve
70
150
50
40
"30
20
10
0.1
0.3
0.5
0.7
CThousands)
tSIE
Figure 2-8:
2-8:
Figure
Curve
Quench
Quench Curve
the
0.9
1.1
Chapter 3: Equipment
3.1
Setup and Instrumentation
General
This
section
contains
a general
description of
the
engine, Laser Induced Fluorescence (LIF), radiometric and Data
Acquisition (DAS) systems.
A detailed equipment breakdown is
contained in Appendix B.
3.2
Engine Description
The test engine was a production, naturally aspirated
Chrysler 2.2 liter, four cylinder engine originally available
in the Dodge Daytona.
The cylinder head for the engine had
been modified to accept piezo-electric pressure transducers
for
cylinder pressure monitoring.
Table
3-1
shows
installed engine instrumentation.
Table 3-1:
Engine Instrumentation
TIndication
Parameter
Temperatures
Coolant into Engine
Type K Thermocouple
Coolant out of Engine
Type K Thermocouple
Oil Sump
Type K Thermocouple
Fuel into Throttle Block
Type K Thermocouple
Intake Air
Type K Thermocouple
Coolant, Cylinder 2
Type K Thermocouple
Liner,. Cylinder 4
Type K Thermocouple
Pressures
the
Engine Instrumentation
Table 3-1:
Parameter
Indication
Cylinder #4 Pressure
Piezo-electric Transducer
w/Charge Amplifier
Intake Manifold
Mercury Manometer
Oil Pump Discharge
Gauge
Fuel Pump Discharge
Gauge
Coolant Head Tank
Gauge
Miscellaneous
Shaft Position
Optical Encoder
Load
Strain Gauge Load Cell
Speed
Magnetic Pulse
The exhaust system was modified to allow separate exhaust
sampling of cylinder number four.
The number four cylinder
exhaust line was insulated to reduce heat loss prior to the
Water
Collection System
insulation
caused higher
(described below) connection;
exhaust
line
temperatures
the
which
required the use of welded flexible fittings instead of the
pre-existing brass fittings.
Test Matrices D and F (Chapter
4) required that the top and second piston ring end-gaps be
pinned to restrict
gap azimuthal motion to
accomplished with notched rings
±10;
and a brass pin
radially into the piston ring groove.
this was
inserted
Figures 3-1 and 3-2
show relevant pinning geometries.
The engine was further modified by the installation of a
quartz window in the number four cylinder wall at the cylinder
coordinates z = 40mm and 0 = 900, referenced respectively from
the fire deck of the engine and from the forward wrist-pin
axis.
Lee provides and an excellent discussion of the window
Pist on Ring
Pin Placer ,ent Scheme
S00,600 <pn hole size)
(Radla.
View)
Pin is made of 0.063' brass
brazing rod
ring groove
4
7-
(ring groove
(pm length) 0.1450
0.0501
(pin hole depth)
Figure 3-1: Pin Schematic
installati on
in the test engine".
Figures
3-240
and 3-34
show the window geometry in detail.
3.3
Laser Induced Fluorescence System (LIF)
The LIF system used in this research was the same as that
39Reference
16, pp 13
4 0Reference 16,
4 1Reference
- 23.
Figure 2-1.
16, Figure 2-2.
described by Shaw, Hoult -and Wong42 .
It consists of two
major subsystems:
Ring Notch
Scheme
Mo -1 k
,
Figure 3-2:
Ring End-gap Notching Scheme
a.
the excitation subsystem and
b.
the fluorescence subsystem.
The dividing point for the two subsystems is the side of the
piston.
Excitation Subsystem
The
excitation
subsystem
consists
of
a He-Cd
laser
radiating at 442 nm, a fiber optic coupling, and a focusing
probe.
in
This subsystem delivers excitation energy to the oil
front of
the number
four cylinder optical window.
fluorescent dye4 3 is dissolved in the oil at a concentration
of 0.15 grams per liter.
42Reference
43Coumarin
Upon excitation, the dye fluoresces
17.
523 available from the Exciton Chemical Company,
Inc.
46
CYUNDER I4
WRIST
PIN
AXIS
FLUORESCED
u'GhT
Figure 3-3:
INCIDENT LIUGh
Quartz LIF Window (Top View)
at a wavelength of 495 nm.
Fluorescence Subsystem
The
fluorescence
subsystem consists
of
the
focussing
probe (shared with the excitation subsystem), a fiber optic
coupling which is coaxial with the excitation fiber optic
cable, a high voltage power supply, a focusing/filtration
unit, a photomultiplier tube
(PMT) and a high gain output
amplifier.
The LIF system outputs a voltage proportional to the oil
film thickness in front of the optical window.
As discussed
in section 2.5, the output is also affected by laser strength,
STROKE
= Y" mm
mm
cER
TG
I
71 mm
XIK
I
30RE = ,.5
I
Figure 3-4:
mm
LNER
Quartz Window Installation (Side View)
PMT high voltage supply and dye
foccussing probe position,
concentration;
output trace calibration is required and is
discussed in Chapter 5.
A schematic of the LIF system was
shown in Figure 2-7.
The
PMT
output
is
a nano-amp
amplification to be usable.
amplifier
with
that
requires
A high gain, low-noise two-stage
a sensitivity
accomplish the desired output.
44Reference 8, pg. 53.
current
of
0.667
V/gA 44
is
used
to
A low pass filter with a cut-
off frequency of 100 kHz is used to reduce the system noise.
3.4
Radiotracer Oil Consumption System (ROCS)
The radiotracer system is a tritium (3H1) tracer system
similar to that reported on by Warrick and Dykehouse4s . Its
major components are the Water Collection System (WCS) and
Liquid Scintillation Counter (LSC), and the Tracer Oil.
Water Collection System
The WCS is piped to the number four cylinder exhaust and
consists of a quartz glass catalytic oxidation tube mounted in
an thermostatically controlled oxidation furnace, a coiled
condenser, a sample receiver and an oil-free sample pump.
schematic of the WCS system is shown as Figure 3-5.
A
The
piping in the system is either laboratory glass or stainless
steel to allow the effective use of heating tape to maintain
sample gas temperature.
The system requires three stainless
steel-to-glass transitions; these are accomplished with graded
seals.
catalyst
A beaded catalyst is used instead of a honeycomb
to
45Reference
facilitate installation in the furnace
14.
tube.
Exhaust Water Collection System
Connect~on
I
Vacuum AdapterExa
Graded Seal
Line Heater
Thernccoupte
Figure 3-5:
Exus
Penum
Samp• e
Co(Lection
Flask
IHI
C
WCS Schematic
Thermocouples are installed to monitor gas and heating tape 46
temperatures;
a variac is
supplied for line heat control.
Supplemental oxygen is supplied to the system just prior to
the furnace entrance.
The oxygen line is heated to reduce
46The
installed heating tapes are "Fibrox" and a temperature
limitation of 4820 C. Several heating tapes must be operated close
to the limit to maintain the exhaust gases entering the furnace at
as high a temperature as possible (500 0 C would be ideal) and
require regular monitoring to prevent burnout. In the future, the
system performance may be improved by replacing the Fibrox tapes
with Samox tapes (760 0 C limit). This would allow higher operating
temperatures and less monitoring.
50
sample
cooling
by
oygen4 7.
the
A purge
valve
and
an
isolation valve are supplied to reduce system stabilization
times subsequent to changes in operating conditions.
The use of glass in the furnace, condenser and collection
flasks
visual
allows
performance48,
catalyst
monitoring
of
performance
and
gross
sample
engine
line
contamination. Appendix B contains photographs of various WCS
details.
Liquid Scintillation Counter (LSC)
The
LSC
system
consists
of
an
automatic
liquid
scintillation analyzer and an analytical balance. The various
pieces of volumetric chemistry equipment are discussed in
appropriate sampling procedures.
Tracer Oil
The tracer oil used is SAE-30W.
Only a small volume of
oil is subjected to the catalytic proton exchange process, but
resulting tracer oil has an extremely high specific activity.
In order to safely handle the tracer oil, it is subjected to
two dilutions.
The tracer stock is stored by the Radiation
Protection Office.
The specific activities of the catalysis
47
If sample cooling occurs prior to the oxidation furnace, the
catalyst efficiency falls; if the cooling occurs between the
oxidation furnace and the condenser, premature condensation can
occur contaminating the sample lines and increasing purge times.
48Gross prbblems in engine operation/performance can be
detected by periodically observing the point where bulk oxidation
(cherry-red glow) is occurring in the catalyst. Experience showed
that during proper operation of the test engine, oxidation started
80% of the way down the furnace tube.
51
sample and the two dilutions are shown in Table 3-3.
Table 3-3:
3.5
Tracer Oil Specific Activities
Dilution
Approximate Specific Activity
(PCi/gram)
Catalysis Sample
7x10 s
Tracer Stock
700
Operating Oil
2 - 5
Data Acquisition System (DAS)
An automatic data acquisition system is used to sample
the pressure in cylinder number four and LIF system output.
The system consists of an IBM 80486 clone with an analogue to
digital conversion card.
The shaft encoder attached to the
forward end of the engine allows 2000 data points to be taken
per crank shaft revolution. Data acquisition is clocked by a
Top Dead Center (TDC) pulse from the shaft encoder. Each data
point
consists
parameters
of
sample
sets
(bursts)
of
up
to
four
(only the two mentioned above were used in this
experiment).
52
Chapter 4:
4.1
Experimental Procedures
General
This section contains a general description of the test
matrix and of the experimental and support procedures used in
this
study
elsewhere.
that
were
not
extant
in
sufficient
detail
The detailed operating procedures and logs may be
found in Appendix C.
The areas covered by this chapter are:
a. WCS design procedure,
b.
test matrices,
c.
radiotracer system validation procedures,
d.
engine/dynamometer operating procedure,
e. LIF/DAS procedure,
f. piston exchange procedures and
g.
4.2
radiological safety practices and procedures.
Water Collection System Design
As
discussed
in
Chapter
Three,
a
Radiotracer
Oil
Consumption System (ROCS) comprises a Water Collection (WCS)
subsystem and a Liquid Scintillation Counter (LSC) subsystem.
Sloan Automotive Engine Laboratory has access to an adequate
LSC at the Radiation Protection Office (RPO), but construction
of a WCS was required.
The WCS was constructed on a portable
lab bench which allowed relatively rapid configuration changes
for system evaluation in much the same way that bread-boarding
functions in electronic design.
Design Objectives:
The basic design for the system is that
developed by Warrick and Dykehouse4 9 .
The specific design
objectives imposed by this project are shown in Table 4-1.
Table 4-1:
WCS Design Objectives
Objective
Priority
Provide Sample Precision of 85%
1
Provide a Maximum Sample Period:
9.4 Minutes/Samples°
2
Minimize Cost
3
Materials:
Design proceeded based upon the assumption that it
would be unrealistic to perform an independent verification of
the oil consumption measurements obtained from the system.
For this reason the material selected for the majority of the
WCS was
various grades
of
laboratory glass;
visual detection of sample line contamination.
of
the
system piping
stainless
steel
to
and
connections
allow minimal
was
piping
this
allowed
The remainder
constructed
corrosion
of
under
typical exhaust gas conditions and to provide maximum heat
transfer where that was necessary.
49Reference
14.
SoThis sample period is based upon achieving 9 samples in a two
hour engine operating period (pinned piston ring operating time
limit) with a 20 minute engine warm-up period and a total of 15
minutes of stabilization time between engine operating conditions.
The implicit assumption of this period is that only steady-state
engine conditions
(as indicated by temperatures) would be
evaluated.
Internal Connections:
the
condenser
All ,system internal connections up to
assembly
were
made
with
metal-to-metal
compression fittings to allow operation at and above 6000
Celsius.
Since the gas flow path was through three different
materials (quartz glass, Pyrex@ glass and stainless steel) it
was
necessary to
accommodate differing thermal
expansion
coefficients with Kovar-to-glass graded seals.
Oxidation:
Exhaust gas oxidation was achieved with a single
thermostated oxidation furnace with a quartz glass oxidation
tube filled with beaded 3-way truck catalyst5 1 . Satisfactory
oxidation
efficiency was
achieved when the
exhaust gases are above 5000 Celsius.
catalyst
and
Due to thermal line
losses, 80 to 90 percent of the catalyst bed length was used
to reheat the exhaust gas to this temperature reducing the
length of catalyst bed available for oxidation; heating tapes
were added to the sampling lines and to the supplemental
oxygen line to reduce the amount of reheating necessary in the
oxidation furnace.
Flow Control:
The number of valves in the flow path was
51The
use of this type of catalyst was based upon availability.
Beaded catalysts are being phased out in passenger car
applications, -but are still available in some truck catalytic
converters. Use of a beaded catalyst allows creation of catalysis
bed in a variety of geometries without specifically designing the
catalyst element to each geometry. Put another way, the catalyst
could be poured directly into whatever shape tube the oxidation
furnace geometry dictated.
55
minimized to reduce the system head loss.
However, it was
necessary to provide the following valves for flow control:
a.
a system isolation valve and
b.
a condenser purge valve.
The system isolation valve became necessary because exhaust
a
system pressure pulses moved ,exhaust gases through the WCS
even when the sample pump (WCS pump) and line heaters were
turned
off
creating
a high
degree
of
WCS
sample
line
contamination during such operations as oil flushes and WCS
system heatup with the engine operating.
The condenser purge
valve allows purging the tritiated water from the condenser
system with ambient air during changes in engine operating
conditions reducing WCS system stabilization times at the new
condition.52
Carry-over Control:
assembly
to
WCS
Carry-over of liquid from the condenser
pump
has
the
following
undesirable
consequences:
a. pump damage,
b.
reduced sample collection rates and
c.
increased pump internal contamination levels.
52
The alternative is to allow the condensers to be "purged"
with tritiated water vapor at the specific activity of the new
operating condition. The difference between these two methods of
purging the condensers (although the analogy is rather rough) can
be thought of as the difference between a fluid system "drain and
fill procedure" and a "feed and bleed procedure".
The air purge
provides a much faster and more thorough removal of activated
sample water from the condenser heat transfer surfaces.
High gas
velocities
in
the area
of
the vacuum adapter
initially created a carry-over rate of approximately 75% of
the condensate.
To prevent this, the vacuum adapter throat
was extended by 12 cm (Figure B-1) and a water trap added
between
the vacuum adapter and the WCS pump.
Operating
experience shows that the throat extension reduces carry-over
to zero percent during normal operation.
If, however, the
level in the sample flask is allowed to reach the tip of the
vacuum adapter throat, splashing of the sample water does
create a minor carry-over problem well within the capacity of
the water trap.
Post WCS Sampling:
WCS validation required that
a post
oxidation furnace total hydrocarbon (HC) sample be taken. The
HC analyzer (HCA) used has a low volumetric flow rate pump
(HCA pump) which is designed to sample exhaust gas that is
supplied at approximately atmospheric pressure. To obtain the
WCS sample period required, WCS flow rates are high and the
post oxidation furnace pressures are well below atmospheric.
The first opportunity in the WCS flow path to effectively
5 3 . To get
withdraw a HC sample is at the WCS pump discharge
an accurate HC sample it was necessary to provide the system
with an "oil-free" vacuum pump.
53Sampling
at this point introduces a mole fraction error
because the water vapor has been taken out of the exhaust gas.
However, this effect can be accounted for stoichiometrically.
57
4.3
Test Matrices
The primary objectives of the project, as discussed in
One,
Chapter
were
broken
down
into
the
following
test
matrices:
Table 4-2:
Objectives and Experimental Groups
Objective
a.
OC Measurement
Validation
b. Direct Observation
of the Effect of Ring
Gap Azimuth (AZ) on Oil
Consumption
c. Correlation of Actual
and Predicted OC
Matrix
Test Matrices
Designation
Condenser
Configuration
Selection
A
02 Flow rate
Optimization
B
Oil Consumption
Map
(Unpinned
Rings)
C
Radiotracer
Measurement
Azimuth
Variation
(Pinned Rings)
D
Hot Ring Gap
Measurement
E
LIF/DAS
Measurement of
Cylinder Film
Thickness and
Pressure
F
To reduce experimental set up time, matrix A was conducted
concurrently with C, and matrix D was conducted concurrently
with F (combined designation: AZ).
Condenser Configuration Selection:
cooling
(circulating) water
The WCS was provided with
connections
to
the
condenser
assembly to accommodate two glass condensers.
Test Matrix A
was designed to select the condenser configuration that gave
the highest sample collection rate.
The parameters on which
the condenser assembly has an impact are:
Three
a.
the sample gas flow rate (head loss) and
b.
the total heat transfer surface.
condenser
types
were
evaluated both
singly
and
combination:
a.
coiled,
b.
Allihn bulb and
c.
Friedrichs.
Matrix A is shown in Table 3-3:
Table 4-3:
Test Matrix A
Parameter
Value or Condition
Engine Speed
2000 and 3000 rpm
BMEP
345 kPa
Condenser Configurations
A
Friedrichs
B
Allihn bulb
C
Coiled
D
Friedrichs and Allihn Bulb
E
Friedrichs and Coiled
Each configuration was evaluated on the following points:
a.
steady-state sample rate (ml/min),
b.
initial sample response time (min) and
c.
purge time.
in
Optimum
Oz
efficiency
Flow
in
Rate:
Typical
an automobile
catalyst
HC
exhaust system is
oxidation
95%."4
about
To improve the efficiency of the catalyst bed of the WCS,
supplemental oxygen is introduced to the exhaust gas sample
just prior to the oxidation furnace.
The supplemental oxygen
also has undesirable effects on the sampling process,
For the purposes of this discussion,
volume
flow
rate;
any
oxygen
displaces exhaust gas sample.
though.
the WCS has a constant
introduced
Furthermore,
to
the
system
because of safety
and geometry consideration, there is only a certain amount of
preheat
that
introduction,
can
so it
be
applied
to
the
oxygen
to
tends to cool the sample thus reducing the
efficiency of the catalyst as discussed above.
the optimum oxygen
prior
flow rate,
the catalytic
To evaluate
efficiency was
evaluated using a HC analyzer at several 02 rates.
Table 3-4
shows the test matrix used.
Table 4-4:
Test Matrix B
Parameter
Value or Condition
Engine Speed (rpm)
2500
BMEP (kPa)
480
Lubricant Condition
SAE 30W / Untritiated
02 Flow Rate (cc/min)
Furnace Conditions*
0, 40, 80, 120 and 160
Bypass and Non-bypass
The two furnace conditions allow measuring the catalyst
efficiency.
5 4Reference
1, pg.
651.
60
Test
Engine
establish
Oil
the
Consumption Map:
normal
characteristics
of
the
(test
test
It was
stand)
engine
desirable
oil
prior
to
consumption
to
alterations of the piston ring configurations.
beginning
In addition,
this test matrix provided an opportunity to meet two other
operational objectives concurrently:
a.
to
evaluate
measurement
the
radiotracer
processes
for
sampling
systemic
errors
and
and
effect corrections and
b.
to allow the engine operators to gain experience
with engine and dynamometer parametric response in
a broad range of operating conditions.
Table 4-5 shows Test Matrix C:
Table 4-5:
Test Matrix C
Parameter
Value or Condition
Engine Speed (rpm)
1500", 2000, 2500, 3000,
350056
BMEP (kPa)
345, 520, 760
Lubricant Condition
SAE 30W / Tritiated
Ring Tensions (N)
Top
22.24 (diametral)
Second
20.90 (diametral)
55Operation
at this speed was considered unsatisfactory because
of large load cell oscillation that could not be filtered out with
the loadcell conditioner; this engine speed was subsequently
deleted from the test matrix.
s6 The first test point at 3500 rpm (bmep = 400kPa) caused the
dynamometer motor-generator set output breaker to trip; the exact
cause of the fault was not determined, but the engine operating
speed was deleted from the test matrix.
Table 4-5':
Test Matrix C
Parameter
Value or Condition
Oil Control
40.47 (tangential)
Direct Observation of Ring Gap AZ Effect on OC:
This test
matrix pinned the top and second piston rings in cylinder
number four.
The second ring was pinned with the gap in the
manufacturer's recommended position. The top piston ring was
Ring End-Gap Locations
(Piston Plan View)
__ý-*hSet
Let
Set atecaef3dd
Poof
Sot
3dSt
Second
FTwoor
Fo
ToO Rlng
Too Ring
Figure 4-1:
Ring NPoUm)
Second Ring
Top Ring Gap Locations
pinned with the gap in four different locations.
shows
f@ AUSet
iwo
schematically
the
location
of
the
Figure 4-1
cylinder
compression .rings in the four configurations used.
four
To reduce
piston-change times, four different pistons/connecting rod
sets were used, one for each configuration.
62
The disadvantage
of this approach is the slight variations in piston/connecting
rod dimensions that may be introduced.
Table 4-6:
Test Matrix D
Parameter
Value or Condition
Engine Speed (rpm)
2000, 2500, 3000
BMEP (kPa)
5
400 (Not used for control)"
Intake Manifold
Vacuum
(inches of Hg)
10
Lubricant Condition
SAE 30w / Tritiated
Piston Ring Data
Gap 0 coordinate (degrees)
Ring
Top
225
81
297
153
Second
45
45
45
45
Data Set
Designation
AZ1/AZ5
*
(Set 1)
AZ2/AZ6
*
(Set 2)
AZ3
AZ4
(Set 3)
(Set 4)
Top Ring Tension
26.6 (Diametral)
(N)
Second Ring Tension
29.4 (Diametral)
(N)
Oil Control Ring
Tension (N)
77.8 (Tangential)
Due to inadequacies of the first set of data taken, AZ1
and AZ2 had to be repeated.
The initial intent of this matrix was to maintain the same
engine hardware as that used in Test Matrix C so that the oil
consumption numbers could be compared on a magnitude basis.
57
was found that it was easier to do one-man testing using
manifold vacuum instead load cell readings because of indication
stabilization times. Although this might appear a major departure
from earlier testing, it was found that BMEP's varied little
between speeds for a given manifold vacuum since all the engine
operating conditions are below the speed for peak torque.
It
However,
inadvertently piston
ring
packs
with
different
tensions were used5 8 making such a comparison impossible.
-GAP-
pth
n
i
tr
iP
P
to
i
GAP
n
uson
ro
Figure 4-2:
Hot Gap Roll-pin Configuration
Hot Ring Gap Measurement:
As discussed in Chapter Two, to
predict OC using GASFLOW and the Shaw Model, it is necessary
to perform iterative calculations to obtain solution closure.
Cherry discussed a method for calibrating GASFLOW to a given
engine.5 9
The method uses adjustments in compression ratio,
second land dimensions
(thermal effects) and ring gaps to
match peak pressure, second land pressure and average blowby
ssIt should be noted that each test matrix is internally
consistent, so oil consumption magnitudes can be compared within a
test matrix.
59Reference
19, section 5.4.
to
of measured values.
five percent
within
Because of
geometric constraints in access to the number four cylinder
liner on the test engine, no measurement
of second land
To overcome this difficulty, one of
pressure was possible.
the geometric degrees of freedom was constrained by measuring
the piston ring gap at operating conditions.
This is done by
drilling a hole into the end of the ring and inserting a rollpin into the hole with the pin end protruding into the gap.
The hole is deeper than the length of the pin.
This allows
the pin to be forced into the gap by the other end of the ring
as the gap closes due to thermal expansion during engine
operation.
The geometry of this arrangement is shown in
Figure 4-2.
The hot ring gap matrix is shown in Table 4-7.
Table 4-7:
Test Matrix E
Parameter
Value or Condition
Engine Speed (rpm)
2500
BMEP (psi)
As necessary to achieve
desired liner temperature
Liner Temperature (OC)
108, 115, 124
Lubricant Condition
SAE 30W / Untritiated
Cylinder Oil Film Thickness and Pressure Measurements:
The
dynamic
are
inputs
used by
the Shaw Model
to predict OC
average second land oil film thickness and cylinder pressure.
These are measured for cylinder number four only using the
Laser
Induced
transducer
Fluorescence
and Data
System, the
Acquisition
System
cylinder pressure
described
in
the
The actual test conditions used for this
previous chapter.
matrix
are
the
same
as
those
for
Matrix D making
Test
simultaneous measurement possible.60
4.4 Engine/Dynamometer Operating Procedures:
The test engine
and dynamometer were operated manually according to the test
procedures included as Enclosures 1 and 2 to Appendix C.
The
safety procedures used were in accordance with applicable
Sloan Automotive Engine Laboratory safety instructions. Where
simultaneous
and
radiotracer
DAS
data
was
collected
two
operators were used.
4.5
Radiotracer Method Validation Procedures:
Since no
external standard could be used to independently measure the
oil
consumption of
the
test
engine
and
thereby providing
explicit validation of the Radiotracer Oil Consumption System
(ROCS), it was necessary to validate the ROCS implicitly by
showing that the system efficiently oxidized all hydrogenated
compounds
sources
to water and by analyzing the
of
error.
(described above)
discharge.
6"Initial
This
and
procedure
measured
the
system for other
used
HC
in
Test
the
Matrix
WCS
B
pump
Concern that the laboratory's only HCA not become
matrix planning did not call for LIF data to be taken
for in the ring gap azimuth matrices. However, preliminary results
from ring configurations AZI and AZ2 indicated that film thickness
measurements would be required. The LIF system was subsequently
hooked up to the test engine and AZ1 and AZ2 configurations
repeated under the designations of AZ5 and AZ6 respectively.
radioactively contaminated, required that the validation be
completed
prior
to
putting
tritiated
oil
in
the
test
engine. 61
4.6
LIF/Data Collection System:
The operating procedure for
the LIF system is described in adequate detail by Deutch62
and Lee63
4.7
Piston Replacement Procedures:
This project required
multiple piston replacements; most of the replacements were
done
on
radiologically
contaminated
components.
Each
replacement procedure was carried out according to the test
engine
maintenance manual.
To
allow
greater
speed
in
completing the replacements, and to prevent errors a detailed
procedure/check-off list was used. This procedure is included
in Appendix C as Enclosure 3.
4.8
Radiotracer Oil Consumption Measurement Procedures:
The
procedures for determining oil consumption rates using the
ROCS are included in Appendix C as Enclosures 4, 5, 6, and 7.
It is important to note that volumetric measures are not used
6 1Revalidation
may be performed in the future, but should only
be accomplished after the engine oil system has been flushed
adequately to produce exhaust water samples that fall below the
RPO's limit for free release. If revalidation is accomplished, it
is recommended- that the operation of the catalyst be checked
concurrently and fresh catalyst added as needed.
62Reference
20, section 2.4.
63Reference
16, pg. 24.
for quantities under 50 ml., This is particularly critical in
performing specific activity measurements on the tracer oil
since
the
oil
measurement.
is
viscous
and
provides
poor
volumetric
The large volume dilutions used are specifically
designed to allow solvation of the oil in a non-viscous, nonpolar
solvent
in
volumes
that
allow
reasonably
accurate
volumetric measures to be made.
All
water and oil
samples
have
to be
prepared
for
counting in the LSC by mixing approximately 1 ml of each
sample with 10 ml of a fluorescing solution.
Experience has
shown that even the use of a micro-pipet introduces as much as
four percent error; therefore, it recommended that LSC sample
size be determined exclusively by gravimetric measurements
done on an analytical balance.
4.9
Radiological
Safety:
Tritium
(3HI)
is
a radioactive
isotope of hydrogen with a 12.6 year half-life.
It emits a
low energy (18.6 keV) beta particle that poses a health threat
only when inhaled, ingested or absorbed into the body.
an
ideal
tracer
isotope
for organic compounds
It is
because
it
freely exchanges with 1H, in normal chemical equilibria and the
difference between the isotopes is transparent to chemical
processes.
The
normal
equilibrium
exchange
of
hydrogen
isotopes can be accelerated through the use of catalysis to
produce
highly
concentrated
tracer
liquids
and
gases.
Although this project used such a tracer, it was in the form
of a viscous, non-polar liquid, that provided little potential
for absorption if handled with the appropriate precautions.
Of greater concern is the tritiated water exhausted by the
engine.
lungs
Water vapor is readily absorbed through the skin and
and
therefore
poses
a much
personnel internal contamination.
contamination,
personnel
the
greater
potential
for
To minimize the risk of
following
radiological
precautions were taken:
iý
Radiological Precautions'
Table 4-8:
Personnel Training
2 hour course given by RPO
Wipe Survey of Test Cell
Weekly
Personnel Urine Sample
Monthly
During Operation: Latex
Gloves
During Maintenance:
Coveralls and Latex Gloves
Protective Clothing
Surface Decontamination
Spot decontamination based
upon wipe surveys
Engine Internal
Decontamination
Pre-maintenance flush
procedure
Retained in test cell
radwaste storage area for
RPO pickup.
Waste Disposal
Prior to the initial introduction of tritium into the test
cell,
the RPO evaluated the flow rate through the exhaust
trench
exhaust
as
providing
water
based
adequate
upon
dispersal
estimated
ventilation flow rates.
69
oil
of
the
tritiated
consumption
and
Chapter 5:
5.1
Results and Discussion of Results
General
This chapter presents the results of the radiotracer
measurement
of
Fluorescence
oil
consumption
and
the
Laser
Induced
(LIF) and pressure data acquired during Test
Matrix AZ (Test Matrices D and F combined).
In addition, the
LIF and pressure data are used to predict oil consumption
using the Shaw Model; the oil consumption predicted by the
model are compared to the radiotracer results.
discussion
of
data
reduction
is included
A preliminary
to
provide
a
background for the interpretation of the results included at
the end of the chapter.
5.2
Radiotracer Oil Consumption System Evaluation
The details of the Radiotracer Oil Consumption System
(ROCS) testing and evaluation are contained in Appendix D.
Table 5-1 summarizes the performance evaluation of the system.
The
ROCS
met
all
the
design
goals
and
was
considered
satisfactory for the continuation of the test matrices.
Table 5-1:
ROCS Performance Evaluation
Criteria
Goal
Actual
Sample Period (min)
9.4
7.7
Error (%)
15
5.4
70
5.3
Data Reduction
The
data
reduction
can
be
divided
into
two
major
categories:
a.
oil consumption measurements, and
b.
Data Acquisition System (DAS) output.
The DAS
output can be
further broken
down into
cylinder
pressure data and oil film thickness data.
Oil
Consumption Measurements:
The
methodology
used
for
computation of test engine oil consumption is discussed at
length by Warrick and Dykehouse64 . A detailed example of the
calculation
is
corresponds
to Sample 1 of
included
included as
Appendix E.
calculations
has
archival
been
in
Appendix A;
this
calculation
the data reduction spreadsheet
All
the
raw
data
transcribed
into
used
Appendix
in
E.
the
An
copy of the original logs has been given to the
supervisor of this thesis.
Data Acquisition System Output:
The Data Acquisition System
output files contain discretized cylinder pressure and film
thickness
signals
in
ASCII
format.
digitizes voltages by allowing 4096 bits
selected.
The
(212)
DAS
reads
and
for the range
The range used in this project was ±10 volts; the
size of a DaS output unit (OU) is therefore:
64Reference 14.
71
OU= 204OOmV
2
4
.88mV
(6.1)
The DAS samples data over a multi-cycle period (10 cycles in
this case);
this allows the creation of intermediate files
containing either multi-cycle averaged data or single-cycle
raw data.
The multi-cycle data reduces random noise in the
resulting pressure and LIF traces.
The single-cycle data
avoids the loss of resolution resulting from cycle averaging
and can be used for the calibration of LIF traces.
The
intermediate files are created using DATAVG, an executable
data averaging code written by Shaw.
After
the
creation
of
the
intermediate
files,
the
pressure and oil film thickness data are processed differently
to provide data files that can be used in GASFLOW and the Shaw
Model.
All computer routines used in the following discussion
were written by the author
routines
is
included
in BASIC.
Appendix F;
as
The text of
the
actual
these
routines
themselves can be found on the thesis data disc under the
directory labeled "Basic".
Cylinder Pressure Data:
The signal sent from the pressure
transducer charge amplifier is a voltage proportional to the
cylinder pressure.
The calibration constant for the entire"
is critical that the pressure transducer, transducer lead
and charge amplifier be used as a complete set after calibration is
conducted.
Substitution of a new component invalidates the
calibration.
65It
pressure signal path is determined by using a hydrostatic
pressure calibration device as excitation and a high-input
impedance voltmeter to read the charge amplifier output. Table
5-2 shows the specific calibration constants.
Table 5-2:
Pressure Transducer Calibration Constants
I
Units
Constant
psi/mV
0.14646
kPa/Mv
1.009854
bar/V
9.9718
All the output files in this project use the units of kiloPascals
(kPa).
The pressure profiles generated for GASFLOW
supply pressure data at two crank angle degree increments.
The pressure signal conditioning is done by the routine titled
PRESSURE.
Because cylinder pressure is the driving force behind oil
consumption in the Shaw Model, the
raw pressure data was
analyzed for the cycle-to-cycle variation in peak pressure
magnitude.
This analysis was performed using a simple maxima
detector in the routine PRESPEAK.
Oil
Film
Thickness
Data:
The
signal
sent
from
the
photomultiplier tube of the LIF system to the DAS is a voltage
proportional
66
to the volume66 of the oil illuminated by the
With a constant illumination beam geometry,
this volume is
proportional to film thickness as discussed in Chapter 2.
focusing probe.
For the reasons discussed in Chapter 2, it
is not possible to determine a fixed calibration constant for
the conversion of DAS output units to film thickness; instead,
it necessary to conduct a calibration evaluation of each
series6 7 of LIF traces.
Film Thickness
Calibration:
The primary method
of
calibration was conducted by matching a piston skirt profile
to portions of that profile observable in the LIF trace.
The
calibration constant for a given set of traces is the factor
that must be applied to the LIF trace to match the amplitude
of the skirt trace.
For this project, the skirt profiles were
measured on a Dektak 8000 surface profile measuring system.
The
linear
resolution
of
this
system
far
exceeds
the
requirements of this project (360 data points per millimeter)
so it was possible to sample the raw profile data at the same
linear spacing as the DAS output file 68 (a maximum resolution
of about 72 data points per millimeter).
Theoretically, the
portion of the piston skirt directly in front of the optical
window (z=40) when the piston passes through top center should
have given the best linear resolution because of the low
67
A series of LIF data is considered to be all the data taken
for a given piston ring configuration. As a practical matter, a
calibration can be considered good for all data taken between the
time the LIF system is completely warmed up (as indicated by a
stable laser output power) and when the system is powered down.
Ensuring that the focusing probe is tightened sufficiently in its
mount to prevent a shift in focus is critical.
68The
linear (z dimension) spacing of individual data points
in the DAS output file is a cosine function since the data are
obtained at a constant crank angle spacing.
piston speed.
In practice,: the portion of the LIF profile
immediately under the oil control ring (z = 27 mm) provided
the best features for profile matching because the piston is
fully flooded with oil at that point and because this tends to
be the lowest wear part of the skirt.
In the set of data designated AZ3 the LIF system was not
.
properly focused.
Typical LIF Trace (Compression and Power Strokes)
120
0uC,
o
.--
0
E
40
250
450
300
Degrees ATC, Exhaust
Figure 5-1:
The
result
Typical LIF Trace
was
a
low
resolution
69Proper
trace
that
provided
focusing consists of adjusting the focusing probe's
location in its threaded mounting hole to achieve the maximum PMT
output voltage for a motoring engine. It was discovered after the
completion of AZ3 that this had not been done properly.
Time
limitations on pinned ring operation (2 hrs per set of rings) had
already been exceeded on the AZ3 rings so no further tests were
possible; it was hoped that normal calibration would correct the
problem.
75
insufficient skirt features
calibration.
An
alternative
calibration of AZ3 traces.
trace
for ±600 of
Several
salient
for accurate profile matching
was
used
for
the
Figure 5-1 shows a typical LIF
Top Center
features
method
(TC) of the power
stroke.
are visible in each trace;
two
features were of special interest in finding an alternative
means of trace calibration.
The first was the oil film under
the lower oil control rail; the second was the trace peak
under the oil control ring.
It was observed on the three
properly focused data series
(AZ4, AZ5 and AZ6) that the
calibrated oil film under the lower oil control rail was of
the same thickness for data sets that were obtained at the
same speed (the load was held constant for all sets in the AZ
Matrix).
It was also noted that the trace peak was of
roughly the same size in all the traces performed at the same
speed.
Since the only difference in the traces was the
azimuthal location of the top ring gap, the above observation
made physical sense also.
Therefore, the AZ3
series was
calibrated by matching the oil film thickness under the lower
oil control rail for the data sets taken at 2000 rpm;
the
trace peak size was used as a second check on the validity of
the method.
The combined surface profile and LIF trace files used for
calibration-were created with a routine called PROMATCH; the
calibrated traces used for further analysis were created with
the routine called LIF.
76
5.4
Test Matrix C (Unpinned Rings) Results
Test Matrix C was conducted with unpinned piston rings in
all cylinders.
It resulted in an oil consumption map for the
test engine.
Figure 5-2 is a scatter plot of the Matrix C
data taken at a bmep of 345 kPa.
The most noteworthy feature
of this graph is the large amount of scatter at 2000 rpm. The
Oi I Consumption vs.
Engine Speed
Unpinned Rings
O0
n~m[
0
oI
I
I
1.9
I
l
2.1
I
2.3
I
2.5
I
I
I
2.7
I
I
I
I
I
2.9
3.1
3.3
CThousands)
rpm
Figure 5-2:
Matrix C Scatter Plot (bmep = 50 psi)
increased number of data points at 2000 rpm was the result of
an effort tG determine if
error;
the scatter was due to experimental
review of the procedures indicates that the data is
accurate.
77
5.5
Test Matrix AZ (Azimuthally" Pinned Rings) Results
Test
thickness
Matrix
AZ
measured
and pressure
oil
oil
film
matrix
was
consumption,
simultaneously.
The
originally designed without the use of LIF and with only the
first four series planned. However, prior to conducting AZ3,
the results of AZ1 became available and indicated that AZ1 and
AZ2 should be rerun with LIF installed.
Therefore, AZ1 and
AZ2 lack oil film thickness data; but the ring configurations
were rerun with LIF under the designation of AZ5 and AZ6
respectively.
thesis
data
The raw DAS data files are contained on the
disk
AZ2DATA, ... etc.
under
the
directories
titled
AZ1DATA,
The intermediate data files are contained
under the directories titled 1DATOUT, 2DATOUT, ... etc.7 1
Oil Consumption Results:
The oil consumption measurements in
Test Matrix AZ were taken with strict accounting of the sample
times.
Figures 5-3 through 5-8 show oil consumption plotted
against median sample time referenced to engine start time;
engine speed for each datapoint is indicated above the point.
In most cases the first sample after changing engine speed
appears to be a transition sample with an oil consumption rate
between the values of the two operating conditions.
70Referenced
to the front of the engine and measured counterclockwise around the circumference.
71
The data locations are listed here so that should questions
arise as to the validity of a given analysis, the data is available
for re-analysis.
27
2.5
2.5
2.4
2.3
2.2
2.1
2
1.8
1
1.7
0
1.5
14
1.3
12
1.1
0.8
0.7
Engon
Fiur 5-:
Figure
5-3:
OC vs
ie
·
OC vs. Time:
OpCeratrng Trwe CmirO
025
AZ1 (0=225)
Engine Operating Time CmTrO
Figure 5-4:
OC vs. Time:
AZ2
2.3
19
1.8
1.7
S18
1.5
O
1.4
1 3 -
8
1.2 1.1
0.9
0.9
0.7
0.
-
05
-
0 .4
-
8
1
10
I
30
I
50
I 70
Engino Operating Time CmrTn
Figure 5-5:
OC vs. Time: AZ3
I
I
90
Engine Operating Trine Cmrnt
I~·
Figure 5-6:
OC vs Time:
AZ4
1.5
1.4
1.3
12
11
I1-
0. 7
O 8
051
0.4
I
10
30
I
50
I
70
I
90
Engine Operating Trme Cmrn)
Figure
5 -7 :
OC vs. Time:
AZ5
I
I
110
I
I
130
24
2.3
2.2
2.1
2
1.9
17
1.4
1,3
1.2
11
09
0.8
07
0.5
0.5
0.4
M1nutes of Engire OperatTon
Figure 5--8:
OC vs. Time:
AZ6
OC vs Top Ring Azimuth
AZ3, AZ4,
AZ2,
AZ5
2. -1
az3
2
1.9
18
17
1.5
1.4
1.3
1.2
3
811
I
0.9
0.8
az2
a.3
0.7
0.5
4
=z2
0.5
..
1 A
.434
l
l
50
I
120
I
10
Azfmuth
0
Figure 5-9:
2000 rpm
+
I
200
240
Thesta degeee)
2500 rpm
Average OC vs. Azimuth
3000 rpm
The average oil consumption7 2 dependence on top ring gap
speed
on
and
azimuth
is
Figures
in
shown
5-9
and
5-10
respectively.
01 1 Consumption vs. RPM
AZ Srre
2.8
C~ump N par)
2.8
2.4
2.2
2
1.5
8
1.4
1.2
I
08
0B
S4
0
Figure 5-10:
3000
2500
2000
alz
+
az2
EngIne Speed
* az3
A
Crpm)
az4
X
az5
V
azS
Average Oil Consumption vs. Engine Speed
Series AZ1 and AZ6 demonstrated unusual behavior at 2500 rpm;
the ring configurations for these series were the same as
those for AZ5 and AZ2 respectively.
Figures 5-11 and 5-12
show the oil consumption plotted against engine speed for both
ring configurations.
72Average
computed without the "transition" points.
01 OConsumption vs.
Azi&AZS Cbm
RPM
5sa p;e
2.9
2.8
2.4
2.2
2
a
1.5
1.5
1.4
1.2
08
04
Eng no
0 azI
+
Crpno
=a5
0
Figure 5-11:
OC vs. Time:
Figure 5-12:
OC vs. Engine Speed (Top Gap @
Ring Gap @ 9=-225
84
)
Pressure
Results:
The .raw cylinder
pressure
analyzed over nine cycles for pressure peaks.
data
was
Each data set
analyzed was then evaluated for the standard deviation of the
peak pressures; the results of this analysis are shown with
error bars in Figure 5-13.
behaved except
at
AZ5,
The peak pressures appear well
2500
rpm.
This
appears
to
be a
significant outlier, although no unusual results were noted in
the oil consumption.
^^~^
3000
az5
az3
az4
az3
az4
az6
T
2500
2500
rpm
02
=
2000
2000
3000
rpm
rpm
iý
1~uu
0
10
5
15
20
Data Set (Groups of 2000, 2500, 3000 rpm)
Figure 5-13:
Cycle Averaged Peak Pressures.
Oil Film Thickness Results:
Figures 5-14 through 5-17 show
the results of the oil film thickness analysis for the second
land on the power stroke.
(from 100 ATC
Figure 5-14 is an expanded view
(Power) to 600 ATC (Power) to show the second
land traces in perspective.
85
100
50
400
390
410
-
2nd Land
420
Degrees ATC, Exhaust
Figure 5-14:
I
Oil Film Thicknesses, AZ3(8=297 0 )
50
5,
40
c,
30
(n
r
20
E
LE
S10
,0
.410
412
414
416
418
420
Degrees ATC, Exhaust
Figure 5-15:
2nd Land Oil Film Thickness, AZ4(0=1530)
I
10
n
410
412
414
416
420
418
Degrees ATC, Exhaust
Figure 5-16:
2nd Land Oil Film Thickness, AZ5(9=225 0)
50
40
n
C
0
E
(n
(,
30
a,
C
S20
E
S
10
0
-410
412
414
416
418
420
Degrees ATC, Exhaust
Figure 5-17:
2nd Land Oil Film Thickness, AZ6 (=81
87
0)
The oil film thicknesses was averaged over the second land.
i3
18
17
1i
14
13
12
11
10
*
7
,IL
a
5
4
3
2
1
0
2000
2500
AZM I
Figure 5-18:
z4 E
az5
3000
azSSo
Average 2nd Land Oil Film Thickness
Figure 5-18 summarizes these results.
Test Matrix E Results:
The piston ring end-gap that exists at
operating
temperatures was measured using rings
prepared73
as
described
in
Chapter
3.
The
specially
rings
were
installed under controlled conditions to prevent impacting the
73The rings were prepared by the Perfect Circle division of the
Dana Corporation.
roll-pin during the use of' a ring compressor.7 4
After ring
installation, the engine was operated at sufficient load to
bring
the
temperatures
into
the
operating
band.
After
temperatures had stabilized, the rings were removed and the
exposed
length
of
roll-pin
measured
using
microscope calibrated to 0.0001 inches.
a
traveling
Table 5-4 shows the
change in the gap size from hot to cold.
Table 5-4: Gap Size Change During Engine Operation
(Nominal Liner Temperature: 116 0 C)
Ring
Change (mm)
Top
0.20
2nd
0.16
This information allows a reasonable estimate of the hot ring
gap of any set of rings used in the test engine if the cold
gap of those rings is known.
5.6 Application of the Shaw Puddle Theory of Oil Consumption
General:
The Shaw Puddle Theory of Oil Consumption has
two distinct parts.
The first is the gas flow prediction
using the Namazian/Heywood Model as implemented in the program
GASFLOW; the second part uses the reverse blowby (RBB)75with
74It
was determined that 25 lb-in. was sufficient torque on the
ring compressor to allow piston installation with out compressing
the pin. This was done by incrementally tightening the compressor
until the piston would go into the cylinder, and then removing the
piston to check the pin length. The piston was then re-installed
using the same torque on the ring compressor.
75Calculated
in GASFLOW.
the
film
thickness
measue.ed
to
experimentally
compute
a
predicted oil consumption.
the difficulties
One of
Calibration of GASFLOW:
in
employing the Shaw Model is "calibrating" the Namazian/Heywood
Model to the particular test engine to which it is applied.
Shaw extended Cherry's work on the calibration of GASFLOW with
a detailed procedure that included the use of the cylinder
pressure, second land pressure and blowby to allow "tuning"
the
hot
engine
results.76
geometry
This
in the model
project
did
not
to produce correct
provide
second
land
pressures because of the geometric limitations of the test
engine; blowby was only measured on test series AZ1 (0=2250)
and
AZ6
(0=810)
limitations.
because
of
equipment
and
scheduling
However, the Test Matrix E measured the hot
piston gap, so some of the pertinent hot engine geometry was
available to limit the number of geometric variables to the
piston-cylinder clearance.
The initially, piston-cylinder clearance (clearance) was
adjusted in an attempt to match the AZ1 blowby.
It was not
possible to match blowby without opening the ring gaps and
then the volume flowrates produced oil consumption rates two
orders of magnitude larger than those measured.
GASFLOW was
Finally,
"calibrated" to the measured OC in AZ5 at 2000
rpm; the calculation necessary for this procedure is included
in Appendix A. The rationale behind such a "back-calibration"
76 Reference
19, pg. 61.
90
is
that
Shaw
derived
empirically based.
s.veral
relationships
that
were
It might reasonably be assumed that there
were perhaps some engine-specific relationships impacting his
relationships for A* and h* (Equations 2.15 and 2.16).
It
should be noted when reviewing the results that the final
blowby rate achieved through the manipulation of GASFLOW was
only 50% of that measured in AZ1 and approximately 25% of that
measured
in
AZ6.
In
addition, to
achieve
the
required
velocity, it was necessary to open the second ring gap to
several times the gap actually existing in the engine; the top
ring end-gap was maintained at
the
size measured in Test
Matrix E.
Shaw Model Results:
Each data set was analyzed with GASFLOW
using the peak pressures
reported above and
obtained in the GASFLOW calibration.
were then
input
into the
the
geometry
The output geometries
Shaw Model.
The
resulting oil
consumption predictions are shown in Figure 5-19 with the
corresponding measured results.
Equation 2.21 states that oil consumption is proportional
to engine speed.
If oil consumption is discussed on a "per
unit time" basis, the engine speed effect tends to mask other
relationships like initial film thickness and Taylor number
dependency.
on
a
Therefore it is useful to discuss oil consumption
"per cycle"
relationships.
basis;
this
tends
The discussion of oil
91
to
unmask
the
other
consumption will
be
shifted to
the per cycle 'basis for the remainder of the
chapter for this reason.
I
Predicted vs. Measured OC
Cconsumptron per Cycle)
13 12
1. 11
0.1
13.09
0 08
1007
0.08
D13.05
0.04
0. 02
0.01
0
M
Figure 5-19:
RE
Wedrcted OC
M Mumured OC
Shaw Model Predictions of Oil Consumption
Predicted vs. Measured OC
CCorralatfon Coeff
= 0 10)
0.034 -
0.032 0 03 0.028 -
0.026 -0
0 024 0.022 C. 02 -
0
0018
-
0. 015
0.014
0.012
D001
0
0i.
[
0
0
008 -
0.008
0.0040 0
I
0.02
I
II
0.04
0.0
D0.0DB
Masured OC (C/cycles)
Figure
5-20:
Predicted
vs.
Measured
Oil
Consumption
5.7
Discussion of Results.'
Correlation
between
Consumption:
Predicted
and
Experimental
Oil
Figure 5-20 shows the predicted OC plotted
against the actual OC. The coefficient of correlation between
the two is only 0.10.77
indicates
that
while
Review of Figure 5-19 for trends
the
measured
oil
consumption
relatively well behaved, the predicted values are not.
is
There
are several possible explanations for this.
a.
Piston Secondary Motion,
b. increased flow resistance along the second land, and
c. oil film thickness azimuthal variation.
To allow evaluation of these effects, it is useful to consider
different azimuthal references. Table 5-5 shows three sets of
translated coordinates:
Table 5-5:
Alternative Azimuthal Coordinates
Ref. to:
Front of
Engine
Coord:
e
Ref. to:
8=2700
8,
Ref. to:
LIF
Window
,w
Ref. to:
2nd Ring
Gap
8,
AZ1/AZ5
225
45
135
180
AZ2/AZ6
81
189
9
36
AZ3
297
27
153
108
AZ4
153
117
63
108
8 is drawn through 360 degrees counter-clockwise, all the
77Post
analysis of Shaw's results indicates that he obtained
approximately an 84% correlation.
other coordinate systems are drawn through 180 degrees of arc
in the shortest direction.
(A)
Stap A: Pstcn cn An6d-Thnut Sidest Lnrer.
Cnk Ange w 15 deare STVC
(8)
So 8: Sccm
Crank Ane -
FnI Irrnacs
t P
dgrs BTDC
I
(C)
Tihnmt Side.
(D)
i
r
Stec C. -c cFPst= Irmcac
ATC
e
czank nde 31 dges
Fiue52:
Figure 5-21:
with Thrust Sce.
Stea0: P.Smn Sta.:izes nIThrt sr e.
C.ank Ant:= AC ce=ees AT C
itnSa
CncpulSqeceo
Conceptual Sequence of Piston Slap
rsCanted.n.i
tna
PizO C-emDt
etyaSofi
DeAzion of e, e
Figure 5-22:
Piston Secondary Motion Geometry
Piston Secondary Motion:
As the piston travels up and
down the liner, a certain amount of rotational freedom is
allowed about the wrist-pin axis by the piston-to-cylinder
clearance.
Figure
5-21
shows
conceptually7" and Figure 5-22
motion."9
the
shows
secondary
motion
the geometry of
that
The geometry that has the largest effect on oil
consumption
78Reference
is
the
clearance
11, Figure 14.
79Reference 21, Figure 2.
between
the
piston
and
the
cylinder during reverse blowby.
It may be seen that if the
piston is inclined away from the top ring gap, the effective
area of that gap will be greater and the gas flow geometry
will be altered.
Intuitively, one would assume that
the
reverse blowby would be increased, but experience with GASFLOW
indicates that the actual effect will depend on the relative
magnitudes of the specific geometries involved.
Figure 5-23
plot the measured oil consumption against the Cosine(0t)08
or
"thrust factor" since the amount that the ring gap is opened
or closed by piston secondary motion can be approximated by a
cosine function when the gap azimuth angle is referenced to a
0 angle of 2700.
There is a definite effect on OC as the
absolute value of the cosine approaches 1.
However, there
seems to be little effect in the intermediate region.
Relative Gap Azimuth:
The second land region may be
thought of as a small pipe or duct with the piston ring gaps
acting as orifices at either end.
The greater the
angle
between the two gaps, the greater the effective "length" of
the land for providing flow resistance.
measured oil consumption plotted against
the top and second ring gaps.
position of
the
two gaps
Figure 5-24 shows
02,
the angle between
Any effect of the relative
is not
clear
from the
results,
although AZ2 (02 = 36) is the lowest oil consumption and has
80
A positive cos(0,)
engine.
corresponds
to the "thrust" side of the
the smallest angular distance from the second ring gap; AZ5
(82 = 180) has only slightly greater cyclic oil consumption
indicating that the flow resistance effect is not dominant.
Oil Film Azimuthal Variation:
Using the LIF system
to observe the second land oil film thickness while making
simultaneous oil consumption measurements has the potential to
provide a useful correlation.
In the case of this project,
0.08
Actual
OC vs.
Acua
OCv."hus
Factor"
"Thrust
atr
0.09
0.07
0.05
,
0.05
o
0.04
0.03
SI
-1
I
-0.5
I
I
I
I
-0.5
-0.2
-0.4
~J
IIIIIIII
0.2
0
0.4
Cornno Thata-t
a
Figue
5-3:
Figure 5-23:
+
2000 rpm
v.
2500 rpm
O
AtualOC
Actual
OC vs. Ot
+
3000 rpm
0.5
0.8
r
the assumption was made that the oil film was constant around
the circumference of the second land; this led to the altering
of the top ring gap azimuth.
Figure 5-25 shows the average
observed oil film thickness plotted against
angle to the LIF window.
e,,
the relative
Comparing the series AZ6 LIF trace
in Figure 5-17 to those of the other data series shows marked
differences in oil film profiles.
Figure 5-26 presents the
2000 rpm AZ6 trace with that of AZ4 (720 from AZ6).
The AZ4
trace shows the typical peak under the top ring; this feature
is deformed or missing entirely on the AZ6 trace.
Since the
AZ6 peaks are the only ones that demonstrated this behavior,
it is reasonable to infer that the proximity of the gap to the
LIF window allows the observation of the oil film deformation
caused by
the gas
flowing
through the
gap.
It
has
the
practical effect of disallowing comparison of the AZ6 traces
with those of other series.
As a direct consequence of this
problem, the Shaw Model predictions will be in error if the
second land oil film thicknesses measured are not the same as
those under the top ring gap.
100
0
Oil Consumption vs.
Relative Azimuth
Raferenced to Seond Ring Ghp
U 12
0 11
0
01
-0
00
0.08
0
0.07
0
0.08
0.05
0
-
0.04
0.03
00
0.02
0.01
I
S
0
30
I
50
I
I
70
I
90
l
I•ltive Azflr.rth Cdgcl
Figure 5--24:
OC vs.
I
I
110
I
130
I
I
150
I
I
170
e)
0,
O( I F1 Im Thickness vs. Relative Azimuth
Rafarrencd
to LIF Window
90
0
7
03
0
L
u
5
a
S
0
0
3
3
0
2
1
-
0
20
40
s0
80
100
120
FPlatfvs Aflmuth Cdesgee)
Figure 5-25:
Oil Film Thickness vs. 02
101
140
180
Post-operation Piston Appeakance:
Each pinned piston, except
the AZ3 piston, was limited to two hours of operation to
prevent scoring the cylinder wall with the ring ends; the AZ3
piston was operated 3.5 hours due to an equipment malfunction.
During operation the pistons developed a set of deposits that
provide interesting insight into the top ring gap gas flow.
Included as Figures G-1 through G-5 of Appendix G, photographs
of these pistons show dramatic differences between pistons
used for different AZ series tests; in these photographs the
a small black dot has been made on the second land marking the
position in which the ring was pinned.
The density of the
deposits on the AZ1 and AZ3 pistons (thrust-side top gap) tend
to be heavier than the deposits present on AZ2 and AZ4 (antithrust-side
gap)
increasing
confidence
that
the
piston
secondary motion plays a major role in oil consumption.
There also appears
to have been a large amount of
interaction between the reverse blowby and the swirl.
This
interaction was the most pronounced in the AZ1 piston where
the reverse blowby gasses left deposits on the second land
only in the clockwise direction. It might be that the reverse
blowby is exacerbated by the dynamic pressure effects
of
swirl.
Anomalous Behavior of AZI and AZ6:
Figures 5-11 and 5-12 show
an unusual increase in the oil consumption for the AZI and AZ6
data sets measured at 2500 rpm.
102
The experimental conditions
were identical to AZ5 and AZ2 respectively. Unfortunately, no
oil film thickness measurements were taken during the AZ1 and
AZ2 data sets.
17)
However, the film thickness traces (Figure 5-
for the AZ6 data series were reviewed for trends and
nothing unusual was found; the pressure traces were similarly
reviewed with negative results for both AZ1 and AZ6.
Another
-possible source of error is the OC measurement itself.
The
original logs of the ROCS were reviewed and nothing unusual
was found.
As of the writing of this thesis, no plausible
explanation has been found.
--
In
40
0
40
3.
E
-
20
€10
A
410
410
414
414
416
416
420
420
Degrees ATC, Exhaust
Figure 5-26:
AZ4 and AZ6; 2nd Land LIF Traces @2000 rpm
103
Chapter 6:
6.1
Conclusions and Recommendations
General
This chapter presents a summary of both the technical
conclusions and practical lessons garnered during the course
of this project.
It also presents recommendations in several
areas, both theoretical and practical, that the author feels
have
the
potential
to impact
future
studies
in
internal
combustion engine oil consumption.
6.2
Conclusions
Radiotracer Oil Consumption System Performance: Measured test
engine oil consumption varied over the range 0.3 g/bhp-hr to
0.9 g/bhp-hr. This is within the expected band for engines of
this
size indicating that
System produces
Evaluation
of
the Radiotracer Oil Consumption
reasonable
the
pinned
results
ring
on
an
results
absolute
scale.
indicates
that
consumption measurements have approximately 8% variability for
a given
set
Radiotracer
consistent
of
Oil
operating conditions,
Consumption
results
to
System
support
the
indicating
produces
test
that the
sufficiently
matrices
of
the
Results
of
oil
project.
Oil
Consumption
versus
consumption measurements
Engine
Speed:
conducted with the
piston
unpinned indicate a modest speed dependence, but
104
rings
a large
.amount of data scatter.
differences.
First,
The results for pinned rings show two
the variability
is
greatly
reduced.
Second, the slope of the linear speed dependence of the oil
consumption varied by a factor of three as
azimuth was changed.
the ring gap
These differences indicate that piston
ring rotation is responsible for the variability of the data
in the unpinned case, and that the azimuth of the top ring gap
plays a major role in determining oil consumption rates.
Relative Ring Gap Azimuth:
There. is no clear relationship
between measured oil consumption and the angular separation
between the
top ring gap and the second ring gap.
This
indicates that the reverse blowby flow through the top ring
gap is not
significantly influenced by
the length of
the
annular space between the two ring gaps.
Absolute
Top
relationship
(measured
Ring
between
from
consumption.
Gap
the
the
Azimuth:
top
forward
ring
There
gap
wrist-pin
is
a
definite
absolute
axis)
azimuth
and
oil
If the gap is located near the center of the
thrust side, oil consumption is maximized, and if the gap is
located
near
the
center
consumption is minimized.
of
the
anti-thrust
side,
oil
This relationship implies that the
tilt and lateral displacement associated with piston secondary
motion effect the oil consumption by varying the "effective
ring gap area."
105
Shaw
Puddle
Theory
of
Oil
Consumption:
There
was
no
quantitative agreement between measured oil consumption and
that
predicted
by
the
mathematical
consumption proposed by Shaw.
correlation
for
oil
This was due, at least in part,
to uncertainty in determining the effective gap area during
reverse blowby and in determining the oil film thickness on
the second land in the vicinity of the top ring gap.
difficulties
azimuthal
arose
due
variations
to
in
piston
average
secondary
second
These
motion
land
oil
and
film
thickness.
However, qualitative analysis shows that the Shaw Puddle
Theory of Oil Consumption is, plausible because variation of
gap
parameters
causes
a
significant
variation
in
oil
consumption.
Anomalous Behavior:
In two instances measured oil consumption
at 2500 rpm (and only 2500 rpm) was a factor of two greater
than expected based upon engine speed and load.
The oil
consumption in these conditions may be governed by mechanisms
which may be important but are, as yet, undetermined.
6.3
Further Study and Analysis
The
following
areas
are
investigation and analysis:
106
suggested
for
further
Analysis of Existing Data:
Data taken in this and other
projects might be analyzed for the following information:
1.
The impact of secondary piston motion on top ring
gap gas velocities.
2.
The
exact
dependence
of
second
thickness on ring gap azimuth.
land
oil
film
Existing data might
provide the basis for this, but it is likely that
the accumulation of more data will be necessary.
New Areas of Investigation:
The following areas are suggested
for future experimentation:
1.
Dual
steadystate
oil
consumption
rate.
Future
investigations of oil consumption, especially on
the Chrysler
2.2
test
engine,
should provide
a
provision for observation of the dual steadystate
oil
consumption rate observed in this project at
2500 rpm during this project.
2.
Second
land
oil
cylinder azimuth.
film
thickness
dependence
on
This will require the ability to
monitor the oil film thickness at several azimuthal
locations around the cylinder.
This
capability
will soon exist in Sloan Engine Laboratory when the
multi-optical window modification is complete to an
existing Kohler Engine.
6.4
Recommendations
and
Observations
Investigations
107
for
Continuing
The following recommendations are based upon the above
conclusions and upon the experience gained in conducting this
experiment.
Radiotracer Oil Consumption System (ROCS): The Radiotacer Oil
Consumption System (ROCS) designed and built for this project
provides adequate accuracy (94.6%) for steadystate and pseudosteadystate measurements
of
engine
oil
consumption
(OC).
There are several design improvements that might be made to
improve system accuracy should that be required; those actions
are discussed below. The system's purge time, initial sample
time and sampling period give the system a time constant that
is between one and two orders of magnitudes higher than that
necessary
to
achieve
transient
and
non-steadystate
measurements of oil consumption.
The
following
changes
are
made
concerning
the
configuration and operation of the ROCS:
1.
The largest impact on the accuracy of the system is
the efficiency of the catalyst.
Should it become
necessary to improve the accuracy of the system,
the following steps will help:
a.
Substitute higher temperature heating tapes
for the sample line heaters.
This will allow
better pre-heating of the sample gases.
b.
Replace the manual heater controls with an
automatic
thermal
108
controller.
This
will
reduce response and warmup times.
c.
Reduce the length of connecting piping in the
Water
Collection
reduce
thermal
System
(WCS).
losses
and
This
will
reduce
the
preheating requirements.
2.
One
of
the most
operations
time
involved
determining
subtractive
the
consuming
in
fuel
8
weighing."
taking
and
inaccurate
ROCS
data
consumption
The
time
rate
involved
is
by
in
taking the data might be reduced by providing an
realtime
fuel
flow measurement
device.
If
the
existing scale must be used, the accuracy can be
improved
at
the
expense
of
sample
period
by
measuring fuel consumption over a long period of
time.
3.
The
ROCS
in
"transition"82
its
current
configuration produces
samples when the engine
conditions are changed because the
operating
system purge
path only purges the condenser assembly.
If the
system isolation valve is replaced with a three-way
valve it will allow the entire
purged.
flow path
to be
However, using air at ambient temperatures
to purge the system will cool the components; this
81This
particular operation was also the single source of
experimental error causing the invalidation of results.
82Discussed
in Chapter 5.
109
configuration
change
should
only
be
made
in
conjunction with the line heating changes discussed
above.
4.
System
modifications
to
allow
other
than
steadystate measurements would be difficult.
transient. oil
consumption
measurement
If
becomes
necessary, it is recommended that an on-line sulfur
dioxide system similar to that reported on by Ariga
et al be created or procured.83
5.
The
ROCS
may
be
used
combustion-ignition
ignition engines.
to
engines
measure
as
the
well
OC
as
in
spark-
However, a soot filter assembly
must be added as described by Hartman.
The use of
such an assembly requires some assumptions about
exhaust content; the researcher using such a system
should
first
satisfy
himself/herself
that
those
assumptions are true for the specific test engine.
Employment of the Shaw Model:
An attempt was made to calibrate the program GASFLOW
using
"hot" gap measurements
measurements.
This
effort
and
did
a reduced
set
not
results
yield
of
state
that
correlated with either blowby or oil consumption measurements.
It is concluded that the only proven method for calibrating
83 Reference
22.
110
GASFLOW is the iterative approach used by Shaw.84
If
it
is necessary to provide the optimum predictive
results from the model, the experimental equipment should be
set up so that the top ring gap is directly illuminated by the
LIF optical window and provisions made for measuring second
land pressure and blowby.
These parameters will allow use of
Shaw's method of calibrating GASFLOW.
Test Engine Operation with Pinned Rings:
The test engine was
operated for up to 3.5 hours with number four cylinder piston
rings pinned in the fashion described in Chapter 3.
After
each set of data, the cylinder liner was examined in detail
for adverse effects; none were noted. The conclusion drawn is
that the 2 hour limit originally imposed on engine operation
with pinned rings is a conservative limit and, as long as the
rings
are properly installed may be exceeded by 75% with
little chance of engine damage.
Engine Decontamination:
the
At the completion of this project,
standard three phase flush
performed on the test engine.
(found in Appendix C) was
The only modification to the
flush procedure was that fresh oil and a fresh filter were
used for each phase.
The dilution factor for the complete
84
Shaw's method uses a sequential adjustment to the engine,
piston and ring geometries to iteratively match peak cylinder
pressure, second land pressure and blowby volume flow rate.
(Reference 9, pg. 61).
11
flush process was 0.008 (the final specific activity was 0.8%
of the
original activity).
This
indicates
that
dilution
factor for each phase (one drain and fill) is about 0.20; this
can
be
used
for
planning
purposes
Protection Office.
112
with
the
Radiation
This Page Intentionally Blank
113
References
i.
Heywood, J. B.: Internal Combustion Engine Fundamentals,
McGraw Hill, 1988.
2.
Johnson, J. H., Bagley, S. T., Gratz, L. D. and Leddy, D.
G.: "A Review of Diesel Particulate Control Technology
and Emissions Effects - 1992 Horning Memorial Award
Lectrue," SAE Paper 940233, 1994.
3.
Wentworth, J. T.: "Effects of Top Compression Ring
Profile on Oil Consumption and Blowby with Sealed RingOrfice Design," SAE Paper 820089, 1982.
4.
"A Systems Approach to
Hill, S. H. and Sytsma, S. J.:
Oil Consumption," SAE Paper 910743, 1991.
5.
Wahiduzzaman et al.: "A Model for Evaporative Consumption
of Lubricating Oil in Reciprocating Engines," SAE Paper
922202, 1992.
6.
Hoult, D. P. and Shaw, B. T. II: "The Puddle Theory of
Oil Consumption," Triboloqy Transactions, Vol. 37, 1994,
pp. 75-82.
7.
Namazian, M. and Heywood, J.: "Flow in the PistonCylinder-Ring Crevices of a Spark-Ignition Engine:
Effect on Hydrocarbon Emissions, Efficiency and Power,"
SAE Paper 820088, 1982.
8.
Hartman, R. M.: "Tritium Method Oil Consumption and its
Relation to Oil Film Thickness in a Production Diesel
Engine," S. M. Thesis, Department of Ocean Engineering,
Massachusetts Institute of Technology, 1990.
9.
"Direct Observation of the Oil
Shaw, B. T. II:
Consumption Mechanism of a Production Single-cylinder
Diesel Engine," S. M. Thesis, Department of Mechanical
Engineering, Massachusetts Institute of Technology, 1992.
10.
Schneider, E. W. and Blossfeld, D. H.:
Measurement of Piston Ring Rotation in
Engine," SAE Paper 900224, 1990.
11.
Ryan et al.:
"Engine Experiments on the Effects of
Design.and Operational Parameters on Piston Secondary
Motion and Piston Slap," SAE Paper 940695, 1994.
12.
Taylor, G. I.: "Deposition of a Viscous Fluid on the Wall
of a Tube," Journal of Fluid Mechanics, Volume X, 1961.
114
"Method for
an Operating
13.
Wu, C., Melodick, T., .Lin, S., Duda, J. and Klaus, E.:
"The Viscous Behavior of Polymer Modified Lubricanting
Oils Over a Broad Range of Temperature and Shear Rate,"
Transactions of the ASME, Journal of Tribology, Vol. 112,
July 1990, pp. 417-425.
14.
Warrick, F. and Dykehouse, R.: "An Advanced Radiotracer
Technique for Assessing and Plotting Oil Consumption in
Diesel and Gasoline Engines," SAE Paper 700052.
15.
Peters, D. G., Hayes, J. M. and Hieftje, G. M.: Chemical
Separations and Measurements: Theory and Practice of
Analytical Chemistry, W. B. Saunders Co., 1974.
16.
Lee, J. M.: "Film Thickness Measurements in a Production
Spark Ignition Engine, " S. B. Thesis, Department of
Mechanical Engineering, Massachusetts Institute of
Technology, 1993.
.17. Shaw, B. T. II, Hoult, D. P., Wong, V. W.: "Development
of Engine Lubricant Film Thickness Diagnostics Using
Fiber Optics and Laser Fluorescence," SAE Paper 920651,
1992.
18.
Hoult, D. P., Lux, J. P., Wong, V. W. and Billian, S. A.:
"Calibration of Laser Fluorescence Measurements of
Lubricant Film Thickness in Engines," SAE Paper 881587,
1988.
19.
Cherry, T. A.: "Gasflow Computer Code Calibration Using
S. M. Thesis,
a Single Cylinder Diesel Engine,"
Department of Ocean Engineering, Massachusetts Institute
of Technology, 1991.
20.
Deutsch, E. J.: "Piston Ring Friction Analysis from Oil
Film Thickness Measurements," S. M. Thesis, Department of
Mechanical Engineering, Massachusetts
Institute of
Technology, 1994.
21.
"A
Wong, V. W., Tian, T., Lang, H. and Ryan, J. P.:
Numerical Model of Piston Secondary Motion and Piston
Slap in Partially Flooded Elastohydrodynamic Skirt
Lubrication," SAE Paper 940696, 1994.
22.
Ariga, S., Sui, P. C. and Shahed, S. M.: "Instantaneous
Unburned Oil Consumption Measurement in a Diesel Engine
using SO2 Tracer Technique," SAE Paper 922196, 1992.
115
Appendix A:
Calculations
This appendix contains calculations in support of various
parts of this thesis; each calculation is provided as a
separate enclosure.
List of Enclosures
Enclosure 1:
Validation Calculations
Spreadsheets
Enclosure 2:
Catalyst Inefficiency Error Calculation
Enclosure 3:
of
Total
Calculation
Consumption System Error
Enclosure 4:
Validation Calculations
Modeling Spreadsheets
Enclosure 5:
Calculation
Flowrate
of
116
Desired
for Oil Consumption
Radiotracer
Oil
for Oil Consumption
GASFLOW
Volumetric
Validation Calculations for Oil Consumption Spreadsheet
I.
Unit Definitions
cm-lIL
g= 1M
sec-= IT
dpm I Q
Ib= g453.6
min -sec-60
ml-=cm
II.
Input Data
Ambient Temperature:
T a := 2 3
(All temperatures are in Celsius.)
Ambient Pressure:
P a.:=769.3
(All pressures are in Torr.)
Relative Humidity:
-1.:=60.0
Engine Speed:
RPM =2033
Load Cell:
Load := 22.2. lb
Initial Fuel Weight:
FW
=62.7. lb
Final Fuel Weight:
FW
=61.5.1b
Fuel Measure Time:
T' 1 = 6.75.min
Activity, Oil Sample:
A
=
Vol, Oil Sample:
V
:= 0.009019.m1
Activity, Water Samp:
66236-dp m
A ,:=38132-dpm
Vol, Water Sample:
V
H/C Ratio, fuel:
SIC
=I ml
=
1.88X
H/C Ratio, oil:
1) =.XX89
Oil Density:
1111
Water Density:
1) = 1.O .9
ml
w
III.
Assumptions
This set of calculations assumes the following:
a. The engine is operating at an equivalence ratio of 1,
b. Linear interpolation for the saturation vapor pressure of water; this
is based upon the assumption that temperature will stay within 5
degrees of 20 degrees Celsius.
117
Encl. 1
IV.
Specific Humidity Calculations
Saturation pressure of water vapor in air at the ambient temperature:
T a- 20
SP
=4.6+ 17.4
5
SP
= 20.16
Torr
Partial Pressure of Water:
H
PP
:= SP
100
12.096
PP=
Ambient Pressure as read from the barometer, must be correct for
temperature effects on the mercury. The appropriate correction are
instrument specific. For the instrument used in this experiment, the
corrections from 15 to 25 degrees Celsius range from approximately -2.0
to -2.25 Torr; correction in all cases of -Torr has been applied.
Corrected ambient pressure:
Pac
a- 2
Pac = 767.3
Torr
The average molar weight of dry air (approximately 20% oxygen and 80%)
nitrogen is 28.8, and the molar weight of water is 18.0. For a given
volume of a gas mixture, the individual gases will occupy the fraction of
the volume corresponding to their partial pressures.
= 18.0
MW,
MW air
=
allI
MW air
232+.828
=
28.8
Specific Humidity (lb H20/lb dry Air):
S
H'[I
HM
PP %vMW NV
(I)
ac:.
) -Mw
air,
H s =0.01
118
Encl. 1
V.
Fuel Rate
FWi- FW f
Rf:-
T I'
R = 1.344 mass time -1
VI.
Water Formation Constants
The water formation constants for fuel and oil (Kf and Ko) express the
number of pounds of water produced for every pound of hydrocarbon
burned. They are calculated from the stoichiometry of the combustion
equation. In each case the single variable is the H/C ratio.
9.HC f
K-
12+ HC f
Kf= 1.219
9.-HC
Ko0
12+ tiC
= 1.2246
K
VII.
Air to Fuel Mass Ratio
To simplify the experimental apparatus, no air flow measurement was taken.
It is therefore necessary to establish the air to fuel mass ratio (Kaf) in
stoichiometric burning.
34.41-IC
K af
12+ H-IC
K af= 4. 6 5 9 4
VIII.
Air Rate
R a : = R fK alr\
_/
cr/·r·r
K a = 6.26O22 ImhSS" 1imle
119
1Encl.
1
IX.
Specific Activities
Specific Activity, Water:
A w
SA
:=-.D
V
SA w= 3.8132- 104 mass -
A
SAo0 -
charge
D 0-
V0
SA o =8.2703- 106 mass -charge
X.
Oil Consumption Rate
The oil consumption rate is calculated from the equations given in SAE
paper #700052.
R fK f+ R a-H
R
"=
SA o
SA
R
-
= 0.0079 -mass'time
120
Encl. 1
Catalyst Inefficiency
Error Calculation
I.
Catalyst Efficiency Calculation
Conc. of Cl1 in exhaust, furnaced bypassed:
Conc. of Cl1 in exhaust, w/ furnace flow:
Catalyst Efficiency:
II.
C im
=
11.4
ppm
ppm
HC fium
H=1
HC bp
Effca t
ElTcat
IHCbp= 715.4
0.984
Unit Definitions:
cm= IL
mole IT
dpm IQ
1
ml cm1
For the purposes of tracking units in this derivation, dpm is called
a unit of charge and a mole is called a unit of time. These
definitions make it possible to use the software for a chemistry
problem instead an engineering one.
III.
Inputs for Error Calculation
H/C ratio for oil:
n = 1.87
Density of oil (20 C):
pi) =O8·XX±
Density of water (20 C):
P % = 0o.999
ml2
Typical Spec. Act., oil:
SA,
Typical Spec. Act.,
SA sample
sample:
121
=734334d(
mi
= 2 4 3 12
Encl.
2
IV.
Unitized Molecular Wt of Oil
For the purpose of this calculation a quantity called the "unitized
oil molecule" is defined as a single carbon atom with a fractional
hydrogen atom equal in'number to the H/C ratio.
V.
UMW
:=(12+ n).-.
mole
UMW
= 13.87 mass time -
Weight Specific Activities
SA
WSA
Weight Specific Activity of Oil:
Po
Weight Specific Activity of Sample:
WSAsample
SA sample
Pw
WSA o = 8.27" 106 .mass I charge
WSA sample = 2.434" 10'4 mass -
VI.
I
charge
Molar Specific Activities
Molar Specific Activity of Oil:
MSA :WSA
t.IJMW
Molar Specific Activity of Sample:
MSA sample
saMilpl
c
MSA
W
4
sample 18.
sa0Pmle
I111rle
= 1.147 108 "ime - ' "charge
MSA saMPl
=
43X)1 l10 5 ine
1
charge
122
Encl. 2
VII.
Molar Water Formation Constant of Oil:
Moles of H20 per Mole of Oil:
K
VIII.
K()
2
= 0.935
Specific Activity (dpm/mole) of Water from Combustion of Oil
MSA
MS
K0
MSA ow= 1.227- 108 * time - • charge
IX.
Mole Fraction of Water from Oil in Sample
F
MSA sample
MSA
,l =O0.004
123
Encl.
2
X.
Mole Fraction of Water from Oil in Exhaust Gases
Total number of moles of gas from combustion of one unitized mole of
oil (since H/C ratio is close to that of fuel):
N
t ::= 1 +
3 77 3
+ 3.773.(i
Ntm
4)+2n
+-
2
N tm = 7.472
Molar fraction of exhaust gas water:
EMF
EMF w
2
Ntm
= 0.125
(The preceeding calculation assumes stoichiometric burning.)
EMF ow :=EMF w"MF ow
EMF
= 4.469 10-4
or
oV
ppn
PPII
:=
EMF-,ow
)W 106
ppmi o\v = 446.852
XI.
Resolving ppm Cl to ppm H20
The actual concentration of unburned hydrocarbons in the oxidation
furnace effluent (given in ppm Cl) can be resolved into the ppm of
H20 that would have been experienced if the hydrocarbons had been
burned. This is done by correcting the ppm C1 by the molar water
formation constant. The potential water thus described is called
"error water".
ppIn e\v : [IClim K o
ppmn ew = 10.659
124
Encl. 2
XII.
Figuring the Error from Inefficiencies in the Catalyst
The upper bound on the error generated because the catalyst does not
fully oxidize the unburned hydrocarbons in the exhaust gases is
evaluated by assuming that all the unoxidized hydrocarbons in the
furnace effluent are from the oil.
Eror catalyst "-
ppn ewv
ppnm ow
Error catalyst = 0.024
Given typical numbers, the maximum error given by catalyst
inefficiency is 2.4%
125
r-•l
2
.~
'
" "
Calculation of Total Radiotracer Oil Consumption System Error
r.
Unit Definitions
g=IM
cm- IL
sec- IT
dpm= IQ
lb- g.453.6
min-sec-60
ml - cm
II.
Input Data
Ambient Temperature:
T :=23
(All temperatures are in Celsius.)
Ambient Pressure:
P a =769.3
(All pressures are in Torr.)
Relative Humidity:
I-I. =60.0
Engine Speed:
RPM
Load Cell:
Load =22.2-lb
Initial Fuel Weight:
FW
=62.7.lb
Final Fuel Weight:
FW
=61.5.l
1
Fuel Measure Time:
1Tf= 6.75.min
Activity, Oil Sample:
t
A0 =6623 66d pm
Vol, Oil Sample:
V 0=0(.009019.ml
=
Aw
Activity, Water Samp:
III.
2033(
38132dpim
= I ml
Vol, Water Sample:
V
H/C Ratio, fuel:
I CI = I.88
H/C Ratio, oil:
IIC
Oil Density:
().888 .
I) =0
Water Density:
D
= 1.89
= 1.0)00.
Assumptions
This set of calculations assumes the following:
a. The engine is operating at an equivalence ratio of 1,
b. Linear interpolation for the saturation vapor pressure of water; this
is based upon the assumption that temperature will stay within 5
degrees of 20 degrees Celsius.
126
Encl. 3
Specific Humidity Calculations
IV.
Saturation pressure of water vapor in air at the ambient temperature:
T a - 20
4.6+ 17.4
SP,
I¢'V
= 20.16
SP
Torr
Partial Pressure of Water:
:= SP
PP
-*
10 0
PP,=12.096
Ambient Pressure as read from the barometer, must be correct for
temperature effects on the mercury. The appropriate correction are
instrument specific. For the instrument used in this experiment, the
corrections from 15 to 25 degrees Celsius range from approximately -2.0
to -2.25 Torr; correction in all cases of -Torr has been applied.
Corrected ambient pressure:
Pac
a=P
Pac =767.•3
Torr
The average molar weight of dry air (approximately 20% oxygen and 80%)
nitrogen is 28.8, and the molar weight of water is 18.0.
For a given
volume of a gas mixture, the individual gases will occupy the fraction of
the volume corresponding to their partial pressures.
= 18.0
MW
MW
a
=.2 32+.8.28
MW ir= 28.8
Specific Humidity (Ib H20/lb dry Air):
PP MW
(Pac-
H
V.
1Iq ) MW air
=0.01
Fuel Rate
Rf:=-
FW - FW
T
127
Encl. 3
R f = 1.344 -mass time-
1
Water Formation Constants
VI.
The water formation constants for fuel and oil (Kf and Ko) express the
number of pounds of water produced for every pound of hydrocarbon
burned. They are calculated from the stoichiometry of the combustion
equation. In each case the single variable is the H/C ratio.
9.HC f
Kf:-
12+ HC f
Kf= 1.219
9-HC 0
12+ HC O
= 1.2246
K
Air to Fuel Mass Ratio
VII.
To simplify the experimental apparatus, no air flow measurement was taken.
It is therefore necessary to establish the air to fuel mass ratio (Kaf) in
stoichiometric burning.
34.4-1 IC
Kaf
12+ H1C
K af =4.6594
VIII.
Ra
R
IX.
Air Rate
=
kRIKK a'
= 6.2622 mnass time -1
Specific Activities
Specific Activity, Water:
A
V
SA,
,,,
= 3.8132* 104 "mass
I
•charge
128
Encl. 3
SA
A
.Do
-o
V
SA o = 8.2703" 106 .mass - ' charge
X.
Oil Consumption Rate
The oil consumption rate is calculated from the equations given in SAE
paper #700052.
R fK f+ RaHs
Ro 0SA 0 Ko
FSA
r\
K o =U.UU/09"mass'tlme
XI.
Error Analysis
1.01 1628
Fuel Rate Error Factor:
Air Rate Error Factor:
E a. =1.011628
Water Pipeting Error:
E \VI = I+ 1()
l(
I +10.10
Ear
Ic
,Cat = 1.024
Catalyst Inefficiency Error Factor:
Oil Pipeting Error:
I
Counting Error Factor:
1C
= I+ I M'5
1.002
od = 1.012
Oil Dilution Error:
'oa
Oil Activity Error:
Eod
opE c
E pEC
I
Water Activity Error Factor:
= 1.0142
' \Va
\•
-pat -c
E v = 1.0262
Activity Ratio Error Factor:
Ear =E wa Eoa
129 E = 1.0407
129 ar
Encl. 3
R fK f÷ R a).H
o SA
•o
w
wSA
Total Error:
E t :=
R -K fE fi RRa'E ar'Hs
SAEo I
Ro
Ko
SA w E ar
1
Et = 0.0542
130
Encl. 3
Validation Calculations
for
Oil Consumption Modeling Spreadsheets
I.
Input Data
A.
Lubricant Specific Data
Density at Reference Coditions (g/ml):
o: =0.888
unit conversion (kg/m^3):
p0o :=Po1
000
P o = 888
Walter's Equation Constants:
m :=
N:= I
Surface Tension @ Reference Conditions (N/m):
a :=.0266
Temp.,
Reference for a (Degrees K):
T
=373
Temp.,
Reference for p (Degrees K):
T :=293
Surface Tension Proportionality Constant:
k =0
B.
Geometric Data
Clearance Between the 2nd Land and Liner:
D-.312
Top Ring End-gap (mm):
g2.376
Length, 2nd Land (mm):
I-4.92
131
Encl. 4
C.
State Data
Temperature, 2nd Land (Degrees K):
T :=450
2nd Land Film Thickness, Initial (mm):
h :=0.008
Initial Assumption for Puddle Radius (mm):
R 3.298
Average End-gap Volumetric Flow Rate (1/min):
Q maxa59.5
6
Q :=Q max
10
60
unit conversion (mm^3/sec):
Q = 9.917- 105
2.
Time to Q.max (sec):
t
Engine Speed (RPM):
N 7m 3000
000555
Calculated Data
A.
Lubricant Data
Low Shear Kinematic Viscosity (m^2/sec):
V := 10'
+ 10N
0.6
v := .0000013
Density:
P: 0 - 0.63. (T- T P)
Low Shear Dynamic Viscosity (kg/(m*sec)):
•t=\vp
ýt= o.U.4_34
a
Low Shear Surface Tension
=
2.294. 10
(N/m):
a =k.(T- T)o) +o
132
Encl. 4
B.
Geometric Data
Reference Radius (mm):
R
= 1.188
Average Velocity over Puddle (mm/sec):
n-U
D.R i-Ro) R
=0.434
U
1000
I100o
U = 489.58
m/sec
T a '-
Taylor Number:
G,
1' = 212.478
(Defined based upon Shaw numbers pending
receipt of lubricant viscosity and
surface tension data.)
Reference Area:
A rf't
T'--
Recalculation of Puddle Radius:
(This calculation is based upon the assumption
that "R", the puddle radius, has the square root
of the puddle area Taylor number dependence. "Ri"
above should be iterated until it is equal to
"R"; this method provides the correct solution to
the simultaneous equations for puddle radius and
average gas velocity, "U".)
4.1
133
Encl. 4
R =3.298
C.
Non-Dimensional Geometric Data
Film Thickness (eq. 22, ref 2):
h star:= 1.30- U. t max)
+0.61
Ta 3
Puddle Area (eq. 21, ref 2):
Astar-
15.28
2
Ta-
3.
Oil Consumption Calculation
(The equations used were adapted from equation 23 of reference 2 to
adjust for input and output units.)
OC cycle
( star) A e A star
10
0C
c
=
6.320- 1()
g/cycle
Cycle per Second:
n -
N2Ipm
n = 25
)C clindr
c\,cl.
Ccvlindcr- = C0.002
()C ylinder 4 1000
O
C engine
OC engine
(g/sec)/cylinder
=
6.326
mg/sec
134
Encl. 4
Calculation of Desired GASFLOW Volumetric Flowrate
1.
Unit definitions:
mm
nIL
mg IM
sec- lT
mE 1000-.mm
dm = 100 nun
g= 1000-mg
kg - 1000. g
min = 60. sec
1:10.6 mm 3
N kg.
2.
2
Given DATA:
Desired OC:
Density of Oil:
OC =.028598-mg
p : 789. kg
'Il
Initial Oil Film Thickness:
h i= .006- mm
Reference Area:
A icf
Dynamic Viscosity of Oil:
t
= 38 in2
kg
0.0I 155
111 scc
N
-(
0.0266 -
Surface Tension of Oil:
I11I
End--cap:
3.
o= .305 m
Non-dimensional Quantity Determination (h* and A* together).
= hi
A
P.h -A ret
4
4
A = 0.04
hA = 0.04
135
Encl. 5
4.
Taylor Number Determination
Iz,-
o
c
Ta : ( O •J.1-6)
I
hA
Ta = 763.099
5.
Velocity Determination:
b = 20
U := Ta-.
It
rat :
t
G
U = 1.757-103
6.
rat = 4.342' 10- 4 . length - 1 time
In
sec
Desired Puddle Radius:
land := 2.
:.
ref
land
r= 2.158 -mn
7.
Desired Q/D ratio:
Ratio := U-
(Iai
1~
2
Ratio =417.833
dill
see
D-
7 n11n1
Q := Ratio.l)
Q = 175.49.min
136
Encl.
5
This Page Intentionally Blank
137
Appendix B:
Equipment
This appendix contains detailed lists of equipment used
during the course of this project. It also contains detail
photographs of three Water Collection System components.
Enclosure 1
Engine Specifications
Enclosure 2
Water
Collection
Specifications
Enclosure 3
Sample Preparation and Counting Equipment
Enclosure 4
Figure B-I:
Modified Vacuum Adapter
Enclosure 5
Figure B-2:
Catalyst Tube
Enclosure 6
Figure B-3:
Water Trap Arrangement
138
System
Equipment
and
Engine Specifications
TYPE
in-line 4 cylinder SOHC
DISPLACEMENT
2.2L
BORE
87.5 mm
STROKE
92 mm
FIRING ORDER
1-3-4-2
NUMBER OF CYLINDERS
4
CYLINDER BLOCK
cast iron
PISTONS
Al alloy
COOLING
water
COMPRESSION RATIO
9.5
RATED POWER
74kW (100hp) @ 5600 rpm
MAXIMUM TORQUE
149 Nm (110 lb-ft) @ 3200 rpm
LUBRICANT
Various
LUBRICANT SYSTEM
Pressure feed-full flow
filtration
COOLING SYSTEM
forced circulation
FUEL
indolene
139
Encl. 1
Water Collection System
Equipment and Specifications
Item
Equipment or Specification
Oxidation Furnace
220 VAC, Lindberg Hevi-Duty, Type 59344
Oxidation Tube
Quartz Glass, 1 inch
Catalyst
Pellet Type, Pt-Pd-Rh 3-way,
AC Rochester Designation HN11024
Condenser
Fredrichs, 24/40
Sample Pump
115 VAC, Oilless Vacuum,
Emerson Model SA55NXGTE-4870
Line Heaters
115 VAC, Tape Type,
Thermolyne Heavy Insulated Fibrox
Temperature Sensor
K type (Chromel/Alumel) Thermocouple
Temperature
Indication
Omega Engineering, Model 175 (4 channel)
Fuel Consumption
Measurement
Balance Scale,
Howard-Richardson, Model 5400
High Temp. Tubing
Pyrex Glass / Stainless Steel
Low Temp. Tubing
Rubber
Hydrocarbon
Analyzer
Flame Ionization Detector,
Rosemount Analytical Model 402
Heater Control
Manually Varied Voltage,
Superior Electric "Powerstat"
Sample Flow
Indication
Wet Test Meter,
Precision Scientific Model 63111
Oxygen Flow
Indication
Flowmeter, Matheson Type 603
Pressure Indication
Manometer, Arthur Thomas Co.
Temperatures
Furnace
6000 Celsius
Max. Heater Tape
482' Celsius
Min.
Condenser-inlet
500 Celsius
Flow Rates
140
Encl. 2
Item
Equipment or Specification
Sample
14.2 1/min
Oxygen
1000 ml/min (optimum)
Sample Collection
Rate
0.5 ml/min
141
Encl. 2
Sample Preparation and Counting Equipment
Item
Sample Weight
Measurements
Micro Pipet
Analyzer
Fluorescing Solution
Equipment
Analytical Balance, Mettler AE200
1000 ml, Medical Laboratory Automation,
Inc.
Liquid Scintillation Analyzer, Packard
Model 2500TR
OptiFluor, Packard Co.
Average Counting
Efficiency
0.41
Sample to Solution
Ratio
1:10
142
Encl. 3
143
Encl. 4
II
I)
~ii
a)
E-o
Hr
o
**
4-)
I
um
$*Hl
(~"'
144
Encl. 5
145
Encl. 6
This Page Intentionally Blank
146
Appendix C:
Operating Procedures and Logs
This appendix presents the final version of the operating
procedures and logs used in this project. They are intended
to be used in conjunction with a system "walk-through" as some
of the terms are not self-explanatory.
Enclosure 1:
Shut-down
Start-up,
Normal
Engine
Emergency Shut-down Procedures
Enclosure 2:
Engine Operating Log
Enclosure 3:
Piston Removal/Installation Procedure
Enclosure 4:
Oil Consumption Measurement
Tritium Tracer Procedures
Enclosure 5:
WCS Sample Log
Enclosure 6:
Procedure for Drawing an Oil Sample
Enclosure 7:
Oil Sample Log Sheet
147
and
Procedure Using
Start-up Procedure
Component
Position or Action
Pre-Startup
Checks
*******
1
Engine Oil
Dipstick
In operating range
2
Engine Coolant
In sight glass
3
Dyno Oil Sump
In sight glass
4
Dyno Foundation
Clear of fluid puddles, Drip pan in
place
5
Engine
Foundation
Clear of oil puddles
6
Fuel Can
Half Full Minimum
*****
Valve Line-up
*****
7
Circulating
(Circ) Water
Supply Valve
(on south wall)
FULL OPEN; check supply pressure 40
to 60 psi on black scale.
8
Circ Water
Supply Manifold
a. Oil Cooler Supply: Check OPEN
b. Coolant HX Supply: Check OPEN
c. Fuel Cooler Supply: Check OPEN
(These are the red handled valves on
the circ water supply manifold)
9
Circ Water
Drain Manifold
Coolant Head Tank Vent Isolation:
Check OPEN
10
Steam Supply
Manifold
Check all valves SHUT
11
Coolant Head
Tank Drain
Valve
Check SHUT
12
Coolant Head
Tank Isolation
Quick-throw
Valves
Check OPEN (in-line position)
Step
r*****
148
Encl. 1
Step
Component
Position or Action
13
@ Fuel Manifold
a. Pump Discharge Control Valve:
Check TO ENGINE position
b. Fuel Return Isolation: Check
OPEN
(both valves should be pointing at
the 9:00 position.)
13a
Oil Cooler
Recirculating
Pump
Check:
a. Coupling is fully mated.
b. Three-way discharge valve is
positioned to discharge to the sump.
14
Power Strips on
back of Control
Panel
Switch ON, light ON
15
Ignition/Fuel
Power Strip
Switch ON, light OFF
16
Heat Exchanger
Oil Out
Setpoint
190 degrees F.
****
Dyno Startup
****
137
"Sloan-lab, GE
Dyno" breaker
in Rm 31-037C
(Key #187)
ON position
(indication light on breaker burned
out) Check indication on Dyno
Control Panel (Blue light)
18
Trench Fan
Controller
ON, light ON.
1.9
MG-SET switch
on Dyno control
panel
ON
20
DYNO REV SWITCH
@Dyno control
panel
REV (starts dyno oil pump)
(allow 5 minute warm-up from this
point before performing step number
24)
21
Power Switch
for Stepper
Motor (rocker
switch @bottom
of Dyno control
cabinet)
ON, light ON
149
Step
Component
Position or Action
22
At Engine
Control Panel
a. RPM display: ON, Light ON
b. Temp Display: ON, Light ON
c. Oil Recirc Pump: ON, Light OFF
d. Load Cell Readout: ON (reading
zero)
23
Dyno MANUAL
RHEO
24
Dyno START
SWITCH
25
Engine OIL
Pressure
Check at "O" position by using the
DYNO rocker switch in the "lower"
direction until you hear the rheostat
click.
**********Critical Step**************
START; MANUAL RHEO to increase speed
to 1200 RPM as indicated by manual
rheo indication of "10".
(Electronic
indication responds too slowly for
this initial adjustment.)
***********Critical Step************
70 to 80 psi, cold
Idiot light off.
IF EITHER LOW PRESSURE OR IDIOT LIGHT
CONDUCT IMMEDIATE DYNO SHUTDOWN (Step
7 of Normal Shutdown Procedure)
26
Load Cell
Readout
Positive (+) number [indicates that
the engine is motoring]
27
@ Dyno
a. Oil Pressure: approx. 10 psi
b. Drip-o-lators: atleast
idrip/5sec.
c. Fan: Positive Air Flow.
28
Wall Fan
ON
Point fan at engine exhaust manifold.
29
Thermocouple
Readouts
Check for proper operation;
means an open thermocouple
****
Engine Startup
****
30
Throttle
manometer
*********Critical Step***********
10 inches of mercury
31
Ignition Switch
ON
Verify 12 to 14 VDC indicated.
32
Load Cell
Readout
Check negative (-) number; indicating
that the engine is firing.
150
"EEE"
Engine Normal' Shutdown Procedure
Step#
Component
Position or action
1
THROTTLE Rocker
10 inches of mercury
2
MANUAL RHEO
1200 RPM
3
THROTTLE Rocker
10 inches of mercury
4
OIL OUT Temp
Maintain light load until less
than 95 degrees Celsius.
5
IGNITION Switch
OFF
6
Load Cell Readout
Check Load (+)
7
OIL OUT Temp
70-80 degrees C for proper
cooldown
****
Secure Dyno
****
8
MANUAL RHEO
*********Critical Step***********
Slew to "0" and immediately:
9
Dyno START SWITCH
STOP
(Counter Clockwise)
10
Dyno REV SWITCH
OFF
(Counter Clockwise)
11
MG-SET SWITCH
STOP
(Counter Clockwise)
12
@ Engine Control
Panel
Take all remaining switches to
OFF.
13
Power Strips of
back of Engine
Control Panel
OFF, light OFF
14
Circ Water Supply
Valve
Shut
15
Dyno Oil Sump
In sight glass
16
"Sloan-lab, GE
Dyno" Breaker in Rm
31-037C (key# 187)
OFF
17
Vent Fan Controller
After visually verifying that no
other lab engines are running,
OFF
151
Emergency Shutdown Procedure
(Oil Trouble Light On)
Step#
Component
Position or Action
1
IGNITION Switch
OFF
2
MANUAL RHEO
Rapidly to "0" and immediately
3
Dyno START SWITCH
STOP
Jrl****
Continue normal
shutdown procedure
****
152
Chrysler 2.2L 'Engine Operating Log
Item
M
i
n
N
o
r
m
M
a
x
Engine Hours
RPM
Throttle
Load Cell
Engine Temperatures
1
2
85
95
95
105
3
4
5
40
6
7
8
9
Oil Press.
70
Ignit. Volts
13
Fuel Press.
20
Coolant Pres.
0
Dyno Oil
Press.
Dyno Sump
Level
2
10
1/2
Dripolators
(1 drip/5 sec)
1: Cooianu into engine
2: Coolant out of engine
3: Oil out of cooler (OOC)
4: Oil Sump
5: Exhaust Gas (OOC)
Fue± into engine
Intake air
8: Coolant, Cylinder 2
9: Liner, Cylinder 4
b:
7:
153
Encl. 2
Piston Removal/Installation Procedure
for Chrysler 2.2 Liter Engine
Tool List:
a. Bundle of Rags
b. Bundle of Paper-towels
c. Head Gasket
d. Manifold Gasket
e. Rubber Bands
f. Q-Tips
g. Gasket Glue
h. Box / open end wrenches:
- 7/16"
- 1/2"
- 9/16"
- 11/16"
- 3/4"
i.
j.
k.
1.
m.
n.
o.
p.
q.
r.
s.
Acetone
U.
Sockets (3/8" drive, 6 point):
- 1/2"
- 8mm
- 10mm
- 13mm
- 13mm deep
- 14mm
- 15mm
Coolant Drain Tank
Oil Drain Tank
500ml beaker
Pliers
Set of slot screwdrivers
Oil drain adapter
Coolant drain adapter
Pipe wrenches:
- 14"
- 24"
Socket drives:
- 3/8" ratchet
- 1/2" ratchet
- 1/2 to 3/8 adapter
- 3/8" long extention
- Two 3/8" short extentions
- 3/8" speed wrench
Electric Drill w/ small brush attachment
Engine oil
Wire toothbush
W. Channel-locks
X.
Nylon Hammer
Y. Ball-pien hammer
Z. Brass "chisel"
aa. Ring Compressor
V.
154
Encl. 3
bb. Thread Protectors,
cc. Torque Wrench: required range 40 to 120 lbf-ft (1/2"
drive, calibrated in "lbf-ft")
dd. Set of Cross-recessed (Philips) screwdrivers.
ee. 12" Crescent Wrench
ff. Special Tool for Cam Pulley alignment.
gg. Anti-seize
Procedure:
#
Tools
Action
Engine Oil Flush
la
Oil Drain Adapter
Drain Tracer Oil, Hang "Do Not
Operate" sign on Dyno Start Switch
lb
Crescent Wrench,
7/8"
Disconnect and cap Oil Cooling
System connections. Be careful not
to cross-thread the swage-lok
fittings.
1c
Flush filter kit.
1st Flush Oil
Remove and store the Tracer Oil
filter; install the 1st Flush
filter.
Fill engine with 1st Flush Oil.
id
le
Operate Engine until oil is 50
degrees C.
Flush filter kit,
2nd Flush Oil
if
ig
Remove and store 1st Flush oil and
filter. Install 2nd flush oil and
filter.
Operate engine until oil is 50
degrees C.
Flush filter kit,
3rd Flush Oil
Remove and store 2nd Flush oil and
filter.
Install 3rd Flush oil and filter.
3rd Flush oil should be the same
grade as the Tracer Oil.
1h
Operate the engine until the oil is
atleast 50 degrees C.
ii
Drain and store 3rd Flush oil and
filter.
Install Tracer Oil filter.
Water Collection System
2
Unplug 110 and 220 VAC.
3
Unplug heaters on sample line.
155
#
Tools
Action
4
9/16"
Disconnect 02 line from sample line,
baq end.
5
9/16"
Disconnect Sample line from furnace
tube; baq ends.
6
Remove sample line bracket from
cart.
7
Remove sample line from exhaust line
bracket.
8
11/16"
Remove sample line from exhaust
line. Cap exhaust line and bag end
of sample line.
9
Disconnect water supply
10
Remove WCS cart. Set up parts cart
on starboard side of engine.
Engine
i1
Isolate coolant head tank.
Unplug all thermocouples on engine.
_12
13
Remove air cleaner.
bench (WB).
14
Unplug pressure sensor.
15
Unplug wire from 02 sensor.
1-6
Unplug sensing lines #6 and #7.
17
Disconnect wiring harness from
throttle block. (4 numbered
connections)
18
Disconnect sparkplug wires.
139
Remove coolant sensor (#5).
20
15mm socket
Set on work
Remove 2 ground connections.
21
Hook up coolant drain adapter under
engine.
22
Disconnect headtank-to-thermostat
hose at thermostat.
23
Coolant Drain Tank
Drain Coolant.
156
#
Tools
Action
24
Coolant Drain Tank
Disconnect coolant by-pass hose at
the thermostat. Drain coolant in
line.
25
Pliers
Disconnect coolant lines to throttle
block.
26
Remove adapter.
27
Disconnect fuel tank and remove.
28
Slot Screwdriver
(SS)
Remove fuel lines from intake
manifold. Retighten hose clamps to
prevent loss.
29
500 ml beaker
Drain residual fuel.
30
31
32
Remove dipstick; place on parts
cart.
33
Shut oil drain valve;
bag adapter.
34
remove and
14" Pipewrench
(PW),
24"PW,
7/16"
Disconnect #4 exhaust line from
mounting bracket.
35
1/2",
1/2"socket
Disconnect main exhaust line.
exhaust donut on parts cart.
36
10mm socket
Remove timing belt cover.
cover on workbench.
37
15mm socket, long
extention.
Loosen timing belt idler pulley.
38
Disconnect #4 cylinder exhaust line.
Put
Place
Slide timing belt off cam pulley.
39
10mm socket,
13mm socket,
long ext.
Remove valve cover.
cart.
40
13mm socket
Remove EGR line. Place EGR line on
parts cart place gaskets and bolts
in throttle block.
41
Place on parts
Disconnect stepper motor.
157
#
Tools
Action
42
10mi socket,
short ext.,
long ext.
Disconnect intake manifold; place
manifold on parts cart.
4:3
10mmi socket, short
ext.,
long ext.
Remove exhaust manifold; place on
parts cart.
44
45
Loosen head bolts according to
loosening sequence diagram.
46
15mm socket
Remove cylinder head; place on parts
cart on rags.
4:7
10mm socket,
8mm socket,
2 short ext.,
long ext.
Remove oil pan.
cart.
48
Rag
Wipe coolant out of cylinders.
49
Q-Tip
Swab headbolt holes in block dry.
50
Elec.Drill,
1" drill
attachment,
Small handheld
steel brushes,
rags,
acetone,
engine oil
Clean cylinder walls.
51
Channel-locks,
Nylon hammer,
Ball-pien hammer,
Brass "chisel"
14mm socket
w/extension.
Remove con-rod bearing caps. Place
on parts cart. When pistons are
available, put caps back on
appropriate con-rods.
52
Hammer handle
Rotate piston to top of stroke.
Then rotate crank free of piston.
Use hammer handle on bottom of
piston to remove piston. Place
piston on parts cart; protect with
Place on parts
-_rag.
Piston Re-installation
53
Bring crank to top of piston stroke.
158
#
Tools
Action
54
Install thread protectors made of
rubber tubing.
55
Stagger compression rings by 180
degrees for design ring position.
See manual for exact azimuthal
position.
56
Oil,
Rags
Smear side of piston with oil.
57
Ring Compressor,
Large SS
Install compressor being careful to
ensure that rings are seated in
groove. Leave 1" protruding at
bottom of skirt.
58
Oil
Put oil on bearing liner and oil
channels.
59
Insert piston in cylinder with the
numbers toward the distributor side.
60
Nylon hammer
Tap compressor level so that the
bottom part is in complete contact
with the top of the block.
61
Hammer handle
Drive piston into place.
62
Rotate crank to BDC for piston while
pushing down on piston.
63
Check bearing liner did not rotate
out of proper position.
64
Thread protectors.
65
Remove thread protectors.
parts cart.
Place on
Inspect bearing cap and liner for
cleanliness and burrs.
66
Oil
Coat liner with oil.
67
14mm socket,
Torque Wrench
Install bearing cap.
Torque to 20 lbf-ft, then to 40 lbfft.
68
10mm. socket,
8mm socket
Install oil pan. Install 8mm bolt
first. Do not tighten until all
bolts are in place.
Timing Setup
159
#
Tools
69
70
Action
Rotate cam follower manually to
purple-purple.
Crossed, recessed
screwdriver(CRS)
3/4"
Rotate crank to zero degrees for #1
cylinder; check that distributor
rotor is pointing to #1 wire.
Cylinder Head Installation
71
Gasket glue,
Q-Tips
Put thin film of glue around the oil
supply hole of the head and the
block (Aft, port side of block).
Use Q-tip to remove the glue from
the edge of the holes.
72
Install head gasket on block.
73
Install cylinder head on block using
bolts for alignment.
74
15mm socket,
Torque wrench
Torque bolts per torquing pattern in
manual.
Step 1: 45 lbf-ft.
Step 2: 65 lbf-ft.
Step 3: 65 lbf-ft.
Step 4: 1/4 turn (> 90 lbf-ft)
Timing Completion
75
Special Tool
76
77
Line up cam pulley per the picture
in the manual.
Install timing belt. Ensure that
the port side (distributor side) is
under tension.
Crescent wrench
Tighten tensioning pulley (CCW)
until timing belt is firm.
Final Installations and Connections
78
13mm deep socket,
10mm socket, long
ext.
Install valve cover. Place two
studs in the front.
(105 lb-in)
79
80
.
81
82
Connect oil cooling system.
Install new manifold gasket.
10mm socket,
short ext.
Install exhaust manifold.
in)
160
(200 lb-
S#
Tools
Action
83
10mm socket,
short and long
ext.
Install intake manifold and throttle
block. (200 lb-in)
84
13mm socket,
short ext.
Install EGR line.
85
15mm socket
Connect 2 cylinderhead ground wires.
86
Re-install sensing lines #6 and #7.
87
SS
Install thermostat and thermostat
by-pass hoses
88
Anti-seize
Install Exhaust lines.
seize compound
89
Pliers
Install coolant lines to throttle
block.
Use anti-
90
Install harness connections to
throttle block.
91
Install thermocouples.
92
Connect 02 sensor.
93
Connect pressure sensor.
94
Connect sparkplug wires.
95
96
Check the PVC line connections to
the valve cover.
97
Check shut the following valves:
-Fuel Drain Valve
-Oil Drain Valve
-Coolant Drain Valve
98
Open the following valves:
- Coolant head-tank isolation.
- Both oil cooling system
isolations.
99
Refill oil system.
100
-
Refill coolant system at head tank.
101
Vent cooling system at thermostat
thermocouple.
102
Conduct pre-operation line-up per
the engine operating instructions.
161
#
102a
Tools
Timing Light
Action
Connect Timing Light and ensure
coolant sensor (#5) is disconnected.
Be careful to position the Timing
Light pickup with the appropriate
side toward the sparkplug.
102b
Remove fuel pump fuse.
102c
Motor engine at 850 RPM
102d
102e
1/2"
Check timing at 12.5 degrees BTC as
indicated on the harmonic balancer.
Adjust timing if necessary by
rotating distributor. If unable to
attain the proper timing with the
distributor, the cam follower must
be readjusted per step 69.
Secure engine.
Remove Timing Light.
Re-install fuse and coolant sensor
(#5).
103
Conduct tightness check on fuel
system by operating pump and
throttling (to 50psi system
pressure) the return line at the
fuel manifold. Check particularly
the connections to the throttle
block.
104
Re-connect WCS. Ensure that 02 line
is connected and 02 isolation valve
is open.
162
Oil Consumption Measurement Procedure
Using Tritium Tracer Procedures
Step
Action
Potential
Radiologic
Hazard
1
Don Surgical Gloves
2
Unplug or switch "off" sample pump.
3
Turn on master power strip.
- Ensure both the thermocouple (TC)
reader and the line heater power strip are
energized.
4
Set TC reader to monitor channel 1:
line temperature.
5
Set Variac at "80".
6
Set furnace at 600 C.
7
Shut Water Collection System (WCS)
isolation valve.
8
Open:
9
Turn on furnace.
Sample
isolation valve,
Sample Bypass Valve,
Circulating Water (CW) throttle
valves on WCS,
CW Manifold Supply (on south wall)
WCS CW isolation on CW manifold
02
10
Bring Engine to operating temperature. This
means that the following conditions exist
for a given set of load conditions:
a. Oil Temp Steady (recirc motor
cycling on the thermostat).
b. Liner Temp Steady.
11
Verify the
initiating
a.
b.
12
Set
13
Start WCS sample pump.
14
Open WCS Isolation Valve
15
Shut slowly, the Sample Bypass Valve.
02
following temperatures prior to
sample flow.
400 <Sample Line Temp<470 C.
Furnace Temp > 550 C.
flow at 27mm on the 603 tube.
163
Encl. 4
Step
Potential
Radiologic
Hazard
16
17
yes
18
yes
Action
Collect 5 minutes of purge water in a round
bottom flask. This ensures that the
tritium concentration in the condensers
will reflect that concentration in the
exhaust gas.
Remove the purge flask and replace with a
sample collection flask (Graduated flask).
Empty the purge flask in the sink and flush
sink. (Regulations allow the disposal of
tritiated water up to the concentration of
100 micro-Curries/ml down a sink drain.)
Collect 10ml of sample:
19
Ensure
during
a.
b.
the following conditions exist
sampling:
Constant Throttle Setting
Constant Dyno Speed setting
Minimum sample time is 5 minutes.
20
During sampling:
a. Fill out sample log sheet.
b. Ensure fuel rate is sampled over a
minimum of a 5 minute period.
c. Fill out a sample label on Radiation
tape with the following information:
H3 1
d.
21
yes
Sample #
Date:
Place label on clean sample vial.
Remove sample flask and replace with purge
flask. (Care should be taken to avoid
breaking the central extention on the
vacuum adapter as this is custom made to
prevent carry-over.)
22
Open Sample Bypass Valve.
23
Shut WCS Isolation Valve.
24
Secure WCS sample pump.
25
yes
Using a pipet bulb and a 10ml pipet,
transfer 5 to 7 ml's of sample to a sample
vial.
164
Step
Potential
Radiologic
Hazard
26
Action
Double check that the sample # is on the
sample vial.
27
yes
Place pipet in contaminated pipet holder.
28
yes
Condensers should be flushed according to
the following procedure prior to changing
sample conditions:
a. Remove condensers
b. Flush with tap water
c. Flush with 50ml of DI water
d. Blow dry with compressed air
29
Secure
a.
b.
c.
d.
the following:
02 supply at the cylinder valve
CW manifold supply and WCS isolation
Furnace
Master power strip.
165
WCS Sample Log
Parameter
Sample #
Date
Ambient Temp
Ambient
Pressure
Relative
Humidity
Engine Parameters
RPM
Throttle
Load Cell
Liner Temp
Oil Sump
Temp
Air Inlet
Temp
WCS Parameters
Line Temp
Gas In Temp
Furnace Temp
Condenser In
Temp
Variac
Setting
Fuel Rate Calculations
Initial Wt.
Final Wt..
Time
Duration
Sample Times
Time Started
166
Encl. 5
I
i
(IParameter I
I
I
I
1
_
I
Time
Isolated
167
I
I
I
I
.
Procedure
for
Drawing an Oil Sample
Step
Equipment
Action
1
Oil Adapter
Don latex gloves and attach adapter
to the oil pan.
2
100 ml mixing
cylinder and
Mettler Balance
Remove the stopper to the cylinder
and place it on the balance, rezero the balance.
3
100 ml mixing
cylinder
Draw approximately a 10 to 20 ml
sample from the oil pan.
4
Mettler Balance
Weigh the oil sample; record
weight.
5
------------------
Allow sample to cool to ambient
temperature.
6
1000 ml buret
Ensure that the buret is full of
heptane or some other non-polar
solvent like toluene.
7
100 ml mixing
cylinder
Dilute the oil sample to between 90
and 99 ml total volume with solvent
from step 5. Record volume under
ist dilution volume. Mix
thoroughly: this means that you
cannot see any oil film on the side
of the mixing cylinder.
8
10 ml graduated
pipet, pipet
bulb,
250
Pipet approximately 10 ml into the
250 ml mixing cylinder. Record
volume transferred (read it off the
pipet).
9
1000 ml buret
Dilute mixture in the 250 ml
cylinder to about 150 ml; record
the total volume.
10
Scintillation
Vial (Glass),
Clean 10 ml
pipet, pipet
bulb.
Transfer between 5 and 10 ml into
the scintillation vial. Ensure that
the cap of the vial is numbered.
-----------
Dispose of rad waste properly and
wash glassware.
11
168
Oil Sample Log Sheet
Sample #:
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
0-
Date:
Oil Designation:
Initial Volume:
Ist Dilution
Vol:
2nd Sample Vol:
2nd Dilution
Vol:
Sample #:
Date:
Oil Designation:
Initial Volume:
1st Dilution
Vol:
2nd Sample Vol:
2nd Dilution
Vol :
Sample #:
Date:
Oil Designation:
Initial Volume:
Ist Dilution
Vol:
2nd Sample Vol:
2nd Dilution
Vol:
Encl
169
7
This Page Intentionally Blank
170
Appendix D:
ROCS Validation and Evaluation
D.1 General: This chapter evaluates the errors involved in
the ROCS, discusses two areas where performance optimization
was conducted and finally makes recommendations as to what
future improvements might be considered.
)D.2
Error Evaluation:
A system error evaluation was
conducted on the ROCS.
The accuracy of the system (A) is
defined as:
(D.1)
A=1-E
where:
E is the aggregate system error.
C.85
during
Test
Matrix
was
on-going
This
analysis
Corrections were made to equipment and sampling techniques to
By the completion of Test
correct problems encountered.
Matrix C, the equipment and procedures were considered mature
and no further modifications to either were made. Table D-1
shows the initial and final evaluations of component errors.
Table D-1:
ROCS Error Evaluation
Measurement
Initial
Error
Final
Error
Oil Dilution
1.7%
1.2%
Fuel Weight
4.2%
1.2%
Oil Sample Preparation
2.0%
0.015%
Water Sample Preparation
1.0%
0.010%
Sample Counting
0.2%
0.2%
Catalyst Inefficiency
2.4%
2.4%
System
10.1%
5.4%
The errors were determined by the following methods:
85To
avoid reducing the validity of that test matrix, the
number of readings of a given measurement was increased so that
those readings could be analyzed statistically; in such cases a
normal distribution was assumed and the mean value was used for
further calculations.
171
Single Measurements:
Each measurement that is used as a
single data point, like a volume measured in a graduated
cylinder, is evaluated by assuming that the error in any
careful measurement can be assumed to be one half of the
finest scale gradation. The percentage error is taken to be
the error divided by a typical measurement.86
Statistical Measurements:
In the cases where there is no
obvious way to evaluate the error (like the LSC or the
micropipet volumes), multiple measurements of a standardized
quantity were made.
The measurements were analyzed for
consistency and the standard deviation taken as the error.
This is an admittedly simplistic approach, but gives a good
indication of the relative magnitude of the system errors.
Catalyst Inefficiency: Obtaining an absolute measure of the
systemic errors caused by the unoxidized hydrocarbons is
difficult; separation of unburned hydrocarbons from the post
catalyst gases is difficult because of the diverse nature of
these compounds and because some are polar enough to be
miscible in exhaust water. As an alternative to an involved
chemical extraction, it was assumed that all the HC leaving
the catalyst bed were derived from the lubricating oil. This
assumption gives an upper bound on the error due to nonoxidation in the catalyst.
Taking as given the geometric
constraints of the catalyst tube, the largest source of
catalyst inefficiency is sample gas entrance temperature. As
part of initial assembly, this temperature was evaluated and
found to be close to 1400 Celsius (3600 from the temperature
required for efficient catalyst operation). Line heaters and
insulation were added increasing entrance temperature to
approximately 2500 Celsius with the line heaters operating
just
below burnout
temperature.
No
further thermal
improvement to the catalyst efficiency was possible.
The
calculation of the catalyst inefficiency error is included as
part of Appendix A.
Multiple Measurement Error: In the case where a parameter is
,derived from multiple measurements
(such as multiple
dilutions) the error was calculated from the following
formula:
86
For exa:riple, if 150 ml of liquid is measured in a 250 ml
graduated
cylinder with
1 ml
gradations,
the
error
is
0.5
E•~me"150
or 0.33 percent.
172
Atotal=1lB
where:
(D.2)
A i is the accuracy of
component measurement.
the
ith
The overall system error was calculated by
System Error:
applying the worst-case error to each measurement and
The
performing a complete oil consumption calculation.
resulting flawed oil consumption rate was then compared to the
This
results of the same calculation without the error.
calculation is included in Appendix A.
Error Reduction:
It was
found that
the volumetric
measurements involved in Oil Dilution, Oil Sample Preparation
and Water Sample Preparation were the principle contributors
to those errors; as many of the volumetric measurements as
possible were changed to gravimetric determinations to reduce
those errors. For example, micropipets were found to have an
error of about 2%; if subtractive weighing on an analytical
balance was used to measure the same quantity of liquid, the
error was approximately 0.015%.
Originally, the largest error in the system was that of
the fuel consumption measurement. This error was reduced by
increasing the length of time over which fuel consumption rate
The optimum appears to be between 8 and 10
was measured.
minutes. Longer samples are not desirable because at least
two samples should be taken at each set of engine operating
conditions to provide a double check (concurrence between the
samples)
D.3 Performance Optimization:
The performance of the ROCS
can be evaluated in two areas:
a. sample rate and
b. measurement accuracy.
Test Matrices A and B were specifically designed to provide
data to aid in performance optimization.
Condenser Configuration: Test Matrix A evaluated the system
performance using five different condenser configurations.
Table D-2 presents the results of that evaluation.
Table D-2:
Condenser Performance
Condenser Configuration
(defined in Chapter 4)
Criteria
A
B
C
D
E
Steady State Sample
0.49
0.47
0.52
0.58
0.65
Rate (ml/min)
173
Table D-2:
Condenser Performance
Condenser Configuration
(defined in Chapter 4)
Initial Sample
Response Time87
(sec)
55
90
58
117
125
Purge Time
312
55
20
>360
>360
(sec)
The twin condenser improved in steady state sample rate,
however, all configurations met the 9.4 minute sample time
Experience showed that the
criteria for a 4 ml sample.
minimum useful sample period is about 8.5 minutes for one-man
operation of the system and the engine; all the ancillary
tasks required in sampling (log keeping, etc.) are actually
more time limiting than the sample period. More important are
the Initial Sample Response and Purge times; these two times
dictate how soon after a change in engine operating conditions
valid samples can be obtained.
Configuration E, a single
c.oiled condenser, is considered the optimum condenser
configuration. In the course of conducting Test Matrix A, it
was discovered that applying vacuum grease to the fittings of
the condenser assembly increased sampling rate by as much as
4,0%. 88
Supplemental Oxygen Flow: To improve the catalyst efficiency
within the constraints discussed above, supplemental oxygen is
added to the sample gas upstream of the catalyst bed. Test
Matrix B was designed to optimize the amount of oxygen added
to the sample; as discussed in Chapter 4, excess supplemental
oxygen slows sampling and can drive down catalyst efficiency
by excess sample cooling.
The system was operated in two
configurations:
a.
Bypass: the oxidation furnace bypassed, and
b.
Non-bypass:
the oxidation furnace in its normal
mode of operation.
This allowed the measurement of non-catalyzed and catalyzed
exhaust gases for varying oxygen flow rates. The resulting
unburned hydrocarbon concentrations
[HC]
were used to
calculate catalyst efficiencies (hat):
87
Initial Sample Response Time is defined as the length of time
from when sample gas flow is initiated until the first drop of
condensate enters the sampling flask.
"8This also indicates that without the grease, the system
develops air leaks that are severe enough to cause noticeable
inaccuracies in the system measurements.
174
byp
[HI
S
[HCI b,-paaa
(D.3)
The results are shown in Figure D-1. Based on these results,
the ratio of the oxygen volume flow rate to the sample volume
flow rate is optimized at 0.074.89
Catalyst Efficiency vs Oxygen Flow Rate
0.985
0.884
0.9 83
0 982
0. 981
0.98
0.979
0 979
0.977
Figure 5-1:
D.4
0
/L
* I
I
0.2
I
I
0.4
I
I
0.8
I
I
I
I
0.8
1
CThousanc•)
Oxygen Flow Rate Ccc/mln)
Supplemental
Efficiency.
Oxygen
I
I
1.2
I
Effect
I
1.4
I
on
I
1.8
Catalyst
System Summary and Future Modifications
The Radiotracer Oil Consumption System developed for this
project has the following performance characteristics:
89In
current configuration of the WCS, a stainless steel ball
reading on the 602 flow tube will give this ratio; it should be
checked frequently for approximately the first half hour of
operation as the components in the oxygen flow path tend to cool
and change the flow from the desired value.
175
Table D-3:
ROCS Performance Summary
Criteria
Goal
Actual
Sample Period (min)
9.4
7.7
Error (%)
15
5.4
As currently configured the system employs a single furnace,
single condenser design. The line heaters are limited to 4820
Celsius and are controlled manually. If future work requires
increased system performance, the following recommendations
are made.
a. System response and sample rates might be improved by
using two parallel coiled condensers.
The two-condenser
designs evaluated by this study were placed in series; a
parallel arrangement would preserve the time response provided
Iby single condensers, but provide the higher sample rate of
dual condensers.
b. The system currently takes about 30 minutes to heat
up to operating line heater temperatures. The line heaters
can only bring the sample gas to 2500 Celsius, requiring an
additional
250
degrees
of
heating
internal
to
the
furnace/catalyst bed. The use of higher temperature heating
tapes and thermostatic line heater control would allow a
faster thermal response in heatup situations and more
efficient catalyst operation.
c. Future construction of a similar ROCS should also
shorten the internal connecting piping as much as possible to
obviate some of the heaters.
176
This Page Intentionally Blank
177
.rpen ix E=
Oil Consumption Spreadsheets
This appendix contains the data reduction spreadsheets
for Test Matrices C and AZ. All the data from the data log
sheets has been transcribed into this appendix.
For the
actual cell contents the original spreadsheets may be
addressed on the thesis disk under the titles:
OILCALC.wkl
and AZOC.wkl. These spreadsheets also contain the pertinent
oil specific activity calculations.
Enclosure 1:
Data Reduction Spreadsheet for Test Matrix C.
Enclosure 2:
Data Reduction Spreadsheet for Test Matrix AZ.
178
Data Reduction Spread Sheet for Test Matrix C
Sample #:
Date:
1
9E+05
2
9E+05
4
9E+05
6
9E+05
7
9E+05
8
9E+05
9
9E+05
LOG DATA
Ambient Temp (deg. C):
23
Ambient Pressure (torr): 769.3
Relative Humidity (%):
60
23
768.8
60
21.5
762.7
61
19.5
767
60
19.5
767
60
19.5
767
60
19.5
767
60
Engine Speed (RPM):
Throttle (indicated):
Load Cell (#):
Liner Temperature:
Oil Sump Temperature:
Air Inlet Temperature:
2033
12.1
22.2
114
90
36
2027
12.1
22.5
113
90
37
2065
11.8
21.8
117
89
30
2004
11.3
20
111
86
33
2004
11.3
20
111
86
33
2016
15.6
29.8
115
89
32
2016
15.6
29.8
115
89
32
Line Temperature:
xh. Gas Into Furnace Temp:
Furnace Temperature:
Condenser Inlet Temp:
Variac Setting:
411
208
645
154
80
417
244
653
163
80
426
242
604
146
83
439
244
631
145
83
439
244
631
145
83
445
249
619
145
83
445
249
619
145
83
Initial Fuel Wt. (lb):
Final Fuel Wt. (lb):
Time Duration (min):
Sample Volume (ml):
Sample Start Time:
Sample Isolation Time:
Duration Time:
Median Sample Times:
62.7
61.5
6.75
62.7
61.5
6.75
49
47.7
6.67
81.3
80.45
5.75
81.3
80.45
5.75
77.8
76.6
5.5
77.8
76.6
5.5
SPECIFIC HUMIDITY SECTION
Corrected Atm.Press.(torr) 767.3
Part.Press.H20 @100%Humid. 20.16
Specific Humidity (g H20/g 0.01
766.8
20.16
0.01
760.7
18.78
0.01
765
16.94
0.008
765
16.94
0.008
765
16.94
0.008
765
16.94
0.008
STOICHIOMETRIC RATIO SECTION
Ko:
1.225
Kf:
1.219
Kaf:
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
FLOW RA.TE SECTION
H/C ratio, oil:
1.89
H/C ratio, fuel:
1.88
Equivalence Ratio::
1
Fuel Rate (g/sec)::
1.344
Air Mass Flow Rate (g/sec) 6.262
1.89
1.88
1
1.344
6.262
1.89
1.88
1
1.473
6.865
1.89
1.88
1
1.118
5.207
1.89
1.88
1
1.118
5.207
1.89
1.88
1
1.649
7.685
1.89
1.88
1
1.649
7.685
ACTIVITY SECTION
Local Sample #:
RPO Sample #:
Date Analyzed:
Sample Activity(dpm):
Sample Volume (ml):
Density of Water (g/ml):
SAw (dpm/g):
SAo (dpm/ml)
Oil Density (g/ml):
SAo (dpm/g):
1
1
8 Feb
38132
1
0.999
38170
7E+06
0.888
8E+06
2
2
8 Feb
36593
1
0.999
36630
7E+06
0.888
8E+06
4
4
8 Feb
22429
1
0.999
22451
7E+06
0.888
8E+06
6
6
8 Feb
22301
1
0.999
22323
7E+06
0.888
8E+06
7
7
8 Feb
24312
1
0.999
24336
7E+06
0.888
8E+06
8
8
8 Feb
13096
1
0.999
13109
7E+06
0.888
8E+06
9
9
8 Feb
14162
1
0.999
14176
7E+06
0.888
8E+06
0.008
7.899
0.008
7.579
0.005
5.073
0.004
3.81
0.004
4.154
0.003
3.297
0.004
3.566
OIL CONSUMPTION SECTION
Rate of O/C (g/sec):
Rate of O/C (mg/sec)
179
Encl.
1
Sample #:
Date:
10
9E+05
, 11
9E+05
12
9E+05
13
9E+05
14
9E+05
15
9E+05
16
9E+05
LOG DATA
Ambient Temp (deg. C):
Ambient Pressure (torr):
Relative Humidity (%):
19.5
767
60
18.5
773
58
18.5
773
58
18.5
773
58
18.5
773
58
18.5
773
58
18.5
773
58
Engine Speed (RPM):
Throttle (indicated):
Load Cell (#):
Liner Temperature:
Oil Sump Temperature:
Air Inlet Temperature:
2008
23.4
44.3
121
90
36
2006
19.1
45.5
120
90
33
2011
19.1
45.5
118
92
32
2506
11.1
19.7
109
92
35
2506
11.1
19.7
109
92
35
2518
15.8
30
114
96
36
2518
15.8
30.1
115
95
35
Line Temperature:
xh. Gas Into Furnace Temp:
Furnace Temperature:
Condenser Inlet Temp:
Variac Setting:
455
255
633
150
83
472
249
531
89
83
459
245
548
110
83
455
250
577
123
83
455
250
577
123
83
450
250
608
126
83
458
252
617
127
83
Initial Fuel Wt. (ib):
Final Fuel Wt. (ib):
Time Duration (min):
Sample Volume (ml):
Sample Start Time:
Sample Isolation Time:
Duration Time:
Median Sample Times:
70.3
68.1
6
65
58.5
16.95
65
58.5
16.95
55.16
53.56
8.05
55.16
53.56
8.05
49
47
7.5
49
47
7.5
SPECIFIC HUMIDITY SECTION
Corrected Atm.Press.(torr)
765
Part.Press.H20 @100%Humid. 16.94
Specific Humidity (g H20/g 0.008
771
16.02
0.008
771
16.02
0.008
771
16.02
0.008
771
16.02
0.008
771
16.02
0.008
771
16.02
0.008
STOICHIOMETRIC RATIO SECTI
Ko:
1.225
Kf:
1.219
Kaf:
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
1.225
1.219
4.659
FLOW RATE SECTION
H/C ratio, oil:
1.89
H/C ratio, fuel:
1.88
Equivalence Ratio:
1
Fuel Rate (g/sec):
2.772
Air Mass Flow Rate (g/sec) 12.92
1.89
1.88
1
2.899
13.51
1.89
1.88
1
2.899
13.51
1.89
1.88
1
1.5
6.99
1.89
1.88
1
1.5
6.99
1.89
1.88
1
2.016
9.393
1.89
1.88
1
2.016
9.393
ACTIVITY SECTION
Local Sample #:
RPO Sample #:
Date Analyzed:
Sample Activity(dpm):
Sample Volume (ml):
Density of Water (g/ml):
SAw (dpm/g):
SAo (dpm/ml)
Oil Density (g/ml):
SAo (dpm/g):
10
10
8 Feb
9417
1
0.999
9427
7E+06
0.888
8E+06
11
11
8 Feb
3137
1
0.999
3140
7E+06
0.888
8E+06
12
12
8 Feb
7436
1
0.999
7444
7E+06
0.888
8E+06
13
13
8 Feb
15598
1
0.999
15613
7E+06
0.888
8E+06
14
14
8 Feb
15886
1
0.999
15902
7E+06
0.888
8E+06
15
15
8 Feb
12640
1
0.999
12653
7E+06
0.888
8E+06
16
16
8 Feb
12448
1
0.999
12461
7E+06
0.888
8E+06
OIL CONSUMPTION SECTION
Rate of O/C (g/sec):
Rate of O/C (mg/sec)
0.004
3.983
0.001
1.382
0.003
3.278
0.004
3.563
0.004
3.629
0.004
3.878
0.004
3.819
180
Encl. 1
Sample #:
Date:
LOG DATA
Ambient Temp (deg. C):
Ambient Pressure (torr):
Relative Humidity (%):
17
9E+05
18.5
773
58
Engine Speed (RPM):
Throttle (Indicated):
Load Cell (#):
Liner Temperature:
Oil Sump Temperature:
Air Inlet Temperature:
3679
12.6
20.2
Line Temperature:
xh. Gas Into Furnace Temp:
Furnace Temperature:
Condenser Inlet Temp:
Variac Setting:
465
258
628
127
83
Initial Fuel Wt. (lb): 37.81
Final Fuel Wt. (lb):
Time Duration (min):
1
Sample Volume (ml):
Sample Start Time:
Sample Isolation Time:
Duration Time:
Median Sample Times:
SPECIFIC HUMIDITY SECTION
Corrected Atm.Press. (torr)
771
Part..Press.H20 @100%Humid. 16.02
Specific Humidity (g H20/g 0.008
STOICHIOMETRIC RATIO SECTI
Ko:
1.225
Kf:
1.219
Kaf:
4.659
FLOW RATE SECTION
H/C ratio, oil:
H/C ratio, fuel:
Equivalence Ratio::
Fuel Rate (g/sec)::
Air Mass Flow Rate (g/sec)
1.89
1.88
1
2.22
10.34
ACTIVITY SECTION
Local Sample #:
RPO Sample #:
Date Analyzed:
Sample Activity(dp:m):
Sample Volume (ml):
Density of Water (g/ml):
SAw (dpm/g):
SAo (dpm/ml)
Oil Density (g/ml):
SAo (dpm/g):
17
17
8 Feb
12448
1
0.999
12461
7E+06
0.888
8E+06
OIL CONSUMPTION SECTION
Rate of O/C (g/sec):
Rate of O/C (mg/sec)
0.004
4.205
181
Encl. 1
Data Reduction Spreadsheet for Test Matrix AZ
Sample #:
Date:
Series::
LOG DATA
40
940315
AZl
41
940315
AZ1
42
940315
AZI
43
940315
AZ1
Ambient Temp (deg. C):
Ambient Pressure (torr):
Relative Humidity (%):
20.5
752
70
20.5
752
70
20.5
752
70
20.5
752
70
Engine Speed (RPM):
Throttle (indicated):
Load Cell (#):
Liner Temperature:
Oil Sump Temperature:
Air Inlet Temperature:
2029
13.9
21
114
87
31
2035
14
21.4
114
91
33
2042
14
21.2
114
89
35
2040
14
21.2
114
90
34
Initial Fuel Wt. (lb):
Final Fuel Wt. (lb):
Time Duration (min):
61.125
58.5313
13.75
61.125
58.5313
13.75
61.125
58.5313
13.75
61.125
58.5313
13.75
Engine Start Time:
Sample Start Time:
Sample Isolation Time:
Duration Time:
Sample Times (ref eng start time):
5
18
28
10
18
5
28
37
9
27.5
5
37
48.5
11.5
37.75
5
48.5
60.5
12
49.5
SPECIFIC HUMIDITY SECTION
Corrected Atm.Press. (torr):
Part.Press.H20 @100%Humid.:
Specific Humidity (g H20/g Air):
750
17.86
0.01067
750
17.86
0.01067
750
17.86
0.01067
750
17.86
0.01067
STOICHIOMETRIC RATIO SECTION
Ko:
Kf:
Kaf:
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
FLOW RATE SECTION
H/C ratio, oil:
H/C ratio, fuel:
Equivalence Ratio::
Fuel Rate (g/sec)::
Air Mass Flow Rate (g/sec):
1.89
1.88
1
1.42609
6.64468
1.89
1.88
1
1.42609
6.64468
1.89
1.88
1
1.42609
6.64468
1.89
1.88
1
1.42609
6.64468
ACTIVITY SECTION
Date Analyzed:
Sample Activity(dpm):
Sample Weight (g):
SAw (dpm/g) :
SAo (dpm/g) :
940316
3615
0.9810
3685.02
8554748
940316
3440
0.9819
3503.41
8554748
940316
3266
0.9445
3457.91
8554748
940316
3284
0.9666
3397.48
8554748
OIL CONSUMPTION SECTION
Rate of O/C (g/sec):
Rate of O/C (mg/sec)
0.00078
0.7798
0.00074
0.74135
0.00073
0.73172
0.00072
0.71892
182
Encl. 2
Sample #:
Date:
Series:
LOG DATA
44
940315
AZ1
45
940315
AZ1
46
940315
AZ1
47
940315
AZI
Ambient Temp (deg. C):
Ambient Pressure (torr):
Relative Humidity (%):
20.5
752
70
20.5
752
70
20.5
752
70
20.5
752
70
Engine Speed (RPM):
Throttle (indicated):
Load Cell (#):
Liner Temperature:
Oil Sump Temperature:
Air Inlet Temperature:
2504
14
21.4
114
93
36
2502
14
21.4
112.5
93
35
2497
14
21.4
113
91
36
2925
14
21.4
114
94
37
Initial Fuel Wt. (ib):
Final Fuel Wt. (ib):
Time Duration (min):
50
47.1875
12.4333
50
47.1875
12.4333
50
47.1875
12.4333
43.8125
39.75
15.7667
Engine Start Time:
Sample Start Time:
Sample Isolation Time:
Duration Time:
Sample Times (ref eng start time):
5
67.9
77
9.1
67.45
5
77
86.5
9.5
76.75
5
86.5
97
10.5
86.75
5
105.8
113.1
7.3
104.45
SPECIFIC HUMIDITY SECTION
Corrected Atm.Press.(torr):
Part.Press.H20 @100%Humid.:
Specific Humidity (g H20/g Air):
750
17.86
0.01067
750
17.86
0.01067
750
17.86
0.01067
750
17.86
0.01067
STOICHIOMETRIC RATIO SECTION
Ko:
Kf:
Kaf:
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
FLOW RATE SECTION
H/C ratio, oil:
H/C ratio, fuel:
Equivalence Ratio:
Fuel Rate (g/sec):
Air Mass Flow Rate (g/sec):
1.89
1.88
1
1.71012
7.96808
1.89
1.88
1
1.71012
7.96808
1.89
1.88
1
1.71012
7.96808
1.89
1.88
1
1.94794
9.07616
ACTIVITY SECTION
Date Analyzed:
Sample Activity(dpm):
Sample Weight (g):
SAw (dpm/g):
SAo (dpm/g):
940316
6705
0.7757
8643.81
8554748
940316
9624
0.9734
9886.99
8554748
940316
9682
0.9626
10058.2
8554748
940316
6526
0.9707
6722.98
8554748
OIL CONSUMPTION SECTION
Rate of O/C (g/sec):
Rate of O/C (mg/sec)
0.0022
2.19501
0.00251
2.51116
0.00255
2.5547
0.00194
1.94412
183
Encl. 2
Sample #:
Date:
Series:
LOG DATA
48
940315
AZI
49
940315
AZI
50
940318
AZ2
51
940318
AZ2
Ambient Temp (deg. C):
Ambient Pressure (torr):
Relative Humidity (%):
20.5
752
70
20.5
752
70
20
750.9
63.5
20
750.9
63.5
Engine Speed (RPM):
Throttle (indicated):
Load Cell (#):
Liner Temperature:
Oil Sump Temperature:
Air Inlet Temperature:
2913
14.05
21.4
114
93
36
2907
14.07
21.8
113
93
36
2053
13.4
21.4
115
89
31
2037
13.4
21.8
115
86
34
Initial Fuel Wt. (lb):
Final Fuel Wt. (lb):
Time Duration (min):
43.8125
39.75
15.7667
43.8125
39.75
15.7667
91.125
88.2188
15.7333
91.125
88.2188
15.7333
Engine Start Time:
Sample Start Time:
Sample Isolation Time:
Duration Time:
Sample Times (ref eng start time):
5
113.1
123.8
10.7
113.45
5
123.8
131
7.2
122.4
38
52
62.5
10.5
19.25
38
62.5
75
12.5
30.75
SPECIFIC HUMIDITY SECTION
Corrected Atm.Press.(torr):
Part.Press.H20 @100%Humid.:
Specific Humidity (g H20/g Air):
750
17.86
0.01067
750
17.86
0.01067
748.9
17.4
0.00944
748.9
17.4
0.00944
STOICHIOMETRIC RATIO SECTION
Ko:
Kf:
Kaf:
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
FLOW RATE SECTION
H/C ratio, oil:
H/C ratio, fuel:
Equivalence Ratio:
Fuel Rate (g/sec):
Air Mass Flow Rate (g/sec):
1.89
1.88
1
1.94794
9.07616
1.89
1.88
1
1.94794
9.07616
1.89
1.88
1
1.39648
6.5067
1.89
1.88
1
1.39648
6.5067
ACTIVITY SECTION
Date Analyzed:
.
Sample Activity(dpm):
Sample Weight (g):
SAw (dpm/g):
SAo (dpm/g):
940316
5136
0.9493
5410.3
8554748
940316
5249
0.9670
5428.13
8554748
940318
2865.57
0.9756
2937.24
8554748
940318
2127
0.8558
2485.39
8554748
OIL CONSUMPTION SECTION
Rate of O/C (g/sec):
Rate of O/C (mg/sec)
0.00156
1.56423
0.00157
1.56939
0.00061
0.60583
0.00051
0.5126
.
184
Encl. 2
Appendix
Sample #:
Date:
Series:
LOG DATA
52
940318
AZ2
53
940318
AZ2
54
940318
AZ2
Ambient Temp (deg. C):
Ambient Pressure (torr):
Relative Humidity (%):
20
750.9
63.5
20
750.9
63.5
20
750.9
63.5
Engine Speed (RPM):
Throttle (indicated):
Load Cell (#):
Liner Temperature:
Oil Sump Temperature:
Air Inlet Temperature:
2026
13.4
21.8
114
85
34
2034
13.4
21.6
114
89
34
2497
13.55
21.4
116
92
36
Initial Fuel Wt. (lb):
Final Fuel Wt. (lb):
Time Duration (min):
91.125
88.2188
15.7333
91.125
88.2188
15.7333
83.5938
80.2188
15.8333
Engine Start Time:
Sample Start Time:
Sample Isolation Time:
Duration Time:
Sample Times (ref eng start time):
38
75
85
10
42
38
85
93.5
8.5
51.25
38
98.5
106.5
8
64.5
SPECIFIC HUMIDITY SECTION
Corrected Atm.Press.(torr):
Part.Press.H20 @100%Humid.:
Specific Humidity (g H20/g Air):
748.9
17.4
0.00944
748.9
17.4
0.00944
748.9
17.4
0.00944
STOICHIOMETRIC RATIO SECTION
Ko:
Kf:
Kaf:
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
1.22462
1.21902
4.65937
FLOW RATE SECTION
H/C ratio, oil:
H/C ratio, fuel:
Equivalence Ratio:
Fuel Rate (g/sec):
Air Mass Flow Rate (g/sec):
1.89
1.88
1
1.39648
6.5067
1.89
1.88
1
1.39648
6.5067
1.89
1.88
1
1.61147
7.50845
ACTIVITY SECTION
Date Analyzed:
Sample Activity(dpm):
Sample Weight (g):
SAw (dpm/g):
SAo (dpm/g):
940318
2364
0.9682
2441.64
8554748
940318
2361
0.9650
2446.63
8554748
940318
2818
0.9629
2926.58
8554748
OIL CONSUMPTION SECTION
Rate of O/C (g/sec):
Rate of O/C (mg/sec)
0.0005
0.50358
0.0005
0.50461
0.0007
0.69657
185
E: Enclosure 2
Encl. 2
This Page Intentionally Blank
186
This Page Intentionally Blank
187
Appendix F:' Basic Routines
This appendix contains the BASIC routines used in this
project. These routines can be run on BASIC interpreter. The
routines are stored on the thesis disk (in the care of the
thesis advisor) in the directory titled "BASIC".
Enclosure i:
LIF.bas
Enclosure 2:
PRESPEAK.bas
Enclosure 3:
PRESSURE.bas
Enclosure 4:
PROMATCH.bas
188
LIF.bas
This routine provides a calibrated LIF trace for the measurement of
film thicknesses. It requires the calibration constant be derived
manually using the traces derived by PROMATCH.
10 OPEN "i",1,"b:az42000b.out"
20 OPEN "o",2,"b:az42000b.lif"
30 LET K=0
40 LET N=0
44 '
45 'Set crank shaft radius
50 LET A=46
54 '
55 'set rough calibration constant for film thickness.
60 LET LS=1
64
65 'set conrod length (mm)
70 LET L=152.4
80 INPUT#1,D
90 LET N=N+l
100 IF N=1 THEN GOTO 80
105 IF N=3 THEN GOTO 40
11.0 LET DEGREE=K*360/2000
12(0 LET THETA=DEGREE*.017453
130 LET Z=A*COS(THETA)+(L^2-A^2*SIN(THETA)A2) ^ .5 - 1 96.5 + 38.1
140 LET V=D*.002441
150 LET FILM=V*LS
160 PRINT#2, DEGREE,Z, FILM
170 LET K=K+I.
180 IF K<4000 GOTO 80
190 CLEAR
200 END
189
Encl. 1
PRESPEAK. bas
This routine calculates the cyclic peak pressures and the crank
angle at which they occur. The routine assumes that the pressures
are contained in a file with two columns in which the pressures are
the first column.
10 OPEN "i", 1, "b:az42000b.dat"
11 LET R=0:LET K=0:LET L=0:LET P2=0:LET P1=0
12 LINE INPUT#1, A$
14 LET R=R+1
15 IF R<44 THEN GOTO 12
20 OPEN "o", 2, "b:az42000b.ppk"
24 CLS
25 INPUT; "Enter pressure test interval:
" , PINTERVAL
26 CLS
30 INPUT; "Enter rise slope trigger:
", ST
31 CLS
32 INPUT; "Enter peak slope threshold:
",PS
33 CLS
34 PRINT "Deg ATC","Pressure"
35 LET M=0
40 LET N=0
50 REM
59 IF L=2000 THEN LET L=0
60 INPUT#1,I
70 LET N=N+l
80 IF N=2 THEN GOTO 40
90 'IF N=3 THEN GOTO 40
95 K=K+l
961 L=L+1
100 LET M=M+1
110 IF M< PINTERVAL THEN GOTO 60
115 LET M=0
120 LET Pl=P2:LET P2=I
130 LET DIFF=P2-Pl
140 IF Q=1 THEN GOTO 160
145 IF DIFF>ST THEN LET Q=1
150 GOTO 60
160 IF DIFF>PS OR P2<580 THEN GOTO 60
170 LET DEGREE=L*360/2000
180 PRINT#2,DEGREE,P2
190 PRINT DEGREE,P2
200 LET Q=0
210 IF K<36000! THEN GOTO 60
220 CLEAR
230 END
190
Encl. 2
PRVESSURE. bas
5 REM "This program uses the cycle-averaged DAS output file as an
input.
It reads the data and uses a counter to determine which
data points are pressure data, and then writes the data to a
pressure output file with the corresponding
crank angle."
10 OPEN "i",1,"b:AZ42000B.OUT"
20 OPEN "o",2,"b:AZ42000B.P"
30 LET K=0:LET D=0
40 N=0
50 REM
60 INPUT#1,I
70 N=N+1
80 IF N=2 THEN GOTO 60
90 IF N=3 THEN GOTO 40
100 LET DEGREE=K*360/2000
110 LET DIFF=D-DEGREE
120 IF ABS(DIFF)>.1 THEN GOTO 150
1:30 D=D+2
140 PRINT#2,D, I
150 K=K+l
160 IF K<4000 THEN GOTO 60
170 IF D<358 THEN PRINT "Less than full cycle data!!!!"ELSE
PRINT"pressure file complete."
180 CLEAR
190 END
191
Encl. 3
PROMATCH. bas
This routine prepares matched surface files for calibration
purposes. The surfaces can then be manipulated in a spreadsheet
program.
10 REM open input & output files
20 INPUT; "Enter name of LIF data file path:
310 CLS
40 INPUT;"Enter
PROFDAT$
name
of
surface profile
data
",LIF$
file path:
50 CLS
60 INPUT; "Enter name of matched profile ouput path:
",MATCHFILE$
70 CLS
80 OPEN"i",1,LIF$
90 OPEN "i",2,PROFDAT$
100 OPEN"o",3, MATCHFILE$
110 REM initialize constants
120 LET Z1=26.797: LET SWITCH=0
130 REM
140 REM
150 REM
160 REM initialize data identifiers: m=profile, n=lif
170 LET M=0
180 LET N=0
190 REM routine to find first z.
200 INPUT#1, LIF
210 LET N=N+1
220 IF N=1 THEN GOTO 200
230 IF N=3 AND SWITCH=0 THEN GOTO 180
240 IF N=3 GOTO 262
250 IF LIF<Z1 THEN GOTO 259
255 GOTO 200
259 LET LIFZ=LIF
260 LET SWITCH = 1
261 GOTO 200
262 N=0
263 GOTO 280
270 REM routine to build a matched profile file. Initial z point
is stored in Lifz, n=0, lif contains a voltage.
280 INPUT #2, PROF
290 LET M=M+1
300 IF M=2 THEN GOTO 360
304 REM convert prof from cm to mm.
305 PROF=PROF*10
308 PRINT PROF,M
310 IF PROF<LIFZ THEN GOTO 400
320 PRINT#3, LIFZ, PROF1
325 PRINT LIFZ,PROF1
330 IF EOF(2) THEN GOTO 370
340 GOSUB 500
350 GOTO 280
360 LET PROF1=PROF
365 GOTO 280
192
Encl 4
370
380
3190
400
405
500
510
5:20
5:30
540
545
550
5650
5'70
CLEAR
PRINT"end of profile data"
END
M=0
GOTO 280
INPUT#1, LIF
LET N=N+1
IF N=1 THEN GOTO 500
IF N=3 THEN GOTO 560
LET LIFZ*=LIF
GOTO 500
PRINT"subroutine is not working"
N=0
RETURN
193
Encl. 4
This Page Intentionally Blank
194
,Appendix G:
Photographs of Piston Deposit Patterns
This appendix presents photographs of the pistons removed
from the number four cylinder after operation. The principal
feature depicted is the deposit pattern on the side of the
piston above the gap pin (designated by a small black dot on
the second land).
Enclosure 1:
AZ Test Pistons; Comparative View
Enclosure 2:
AZI Close-up
Enclosure 3:
AZ2 Close-up
Enclosure 4:
AZ3 Close-up
Enclosure 5:
AZ4 Close-up
195
5i
11
/
I
--
'A
I
Ft
Y
196
Encl. 1
197
Encl.2
Nw
K
198
Encl. 3
C
03
00
Ne
N
'ii;,
199
IC
Encl. 4
NJ~
200
Encl. 5